MapStream (Speedment 2.3.7 API)

java.lang.Object
- com.speedment.stream.MapStream<K,V>

Type Parameters:

K - the key type

V - the value type

All Implemented Interfaces:

AutoCloseable, BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>, Stream<Map.Entry<K,V>>
```
public final class MapStream<K,V>
extends Object
implements Stream<Map.Entry<K,V>>
```
A java Stream wrapper that stream over Key-Value pairs. With this wrapper you get access to additional operators for working with two valued collections.

Author:

Emil Forslund

Nested Class Summary
- Nested classes/interfaces inherited from interface java.util.stream.Stream
  Stream.Builder<T>

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`allMatch(BiPredicate<? super K,? super V> predicate)` Returns whether all key-value pairs of this stream match the provided predicate.
`boolean`	`allMatch(Predicate<? super Map.Entry<K,V>> predicate)` Returns whether all elements of this stream match the provided predicate.
`boolean`	`anyMatch(BiPredicate<? super K,? super V> predicate)` Returns whether any key-value pairs of this stream match the provided predicate.
`boolean`	`anyMatch(Predicate<? super Map.Entry<K,V>> predicate)` Returns whether any elements of this stream match the provided predicate.
`void`	`close()` Closes this stream, causing all close handlers for this stream pipeline to be called.
`<R,A> R`	`collect(Collector<? super Map.Entry<K,V>,A,R> collector)` Performs a mutable reduction operation on the elements of this stream using a `Collector`.
`<R> R`	`collect(Supplier<R> supplier, BiConsumer<R,? super Map.Entry<K,V>> accumulator, BiConsumer<R,R> combiner)` Performs a mutable reduction operation on the elements of this stream.
`static <K> Comparator<K>`	`comparing(Function<K,? extends Comparable<?>>... methods)` Utility method for creating a composed comparator that begins by comparing the first value and if it is equal, continues to the next one.
`long`	`count()` Returns the count of elements in this stream.
`MapStream<K,V>`	`distinct()` Returns a stream consisting of the distinct elements (according to `Object.equals(Object)`) of this stream.
`MapStream<K,V>`	`distinctKeys()` Returns a stream consisting of the distinct elements (according to `Object.equals(Object)`) of this stream based on the key only.
`MapStream<K,V>`	`distinctKeys(BinaryOperator<V> merger)` Returns a stream consisting of the distinct elements (according to `Object.equals(Object)`) of this stream based on the key only.
`MapStream<K,V>`	`distinctValues()` Returns a stream consisting of the distinct elements (according to `Object.equals(Object)`) of this stream based on the value only.
`MapStream<K,V>`	`distinctValues(BinaryOperator<K> merger)` Returns a stream consisting of the distinct elements (according to `Object.equals(Object)`) of this stream based on the value only.
`static <K,V> MapStream<K,V>`	`empty()` Constructs an empty `MapStream`.
`MapStream<K,V>`	`filter(BiPredicate<? super K,? super V> predicate)` Returns a stream consisting of the elements of this stream that match the given predicate.
`MapStream<K,V>`	`filter(Predicate<? super Map.Entry<K,V>> predicate)` Returns a stream consisting of the elements of this stream that match the given predicate.
`MapStream<K,V>`	`filterKey(Predicate<? super K> predicate)` Returns a stream consisting of the elements of this stream where the key component matches the given predicate.
`MapStream<K,V>`	`filterValue(Predicate<? super V> predicate)` Returns a stream consisting of the elements of this stream where the value component matches the given predicate.
`Optional<Map.Entry<K,V>>`	`findAny()` Returns an `Optional` describing some element of the stream, or an empty `Optional` if the stream is empty.
`Optional<Map.Entry<K,V>>`	`findFirst()` Returns an `Optional` describing the first element of this stream, or an empty `Optional` if the stream is empty.
`<R> Stream<R>`	`flatMap(BiFunction<? super K,? super V,? extends Stream<? extends R>> mapper)` Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`<R> Stream<R>`	`flatMap(Function<? super Map.Entry<K,V>,? extends Stream<? extends R>> mapper)` Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`<R> MapStream<R,V>`	`flatMapKey(BiFunction<? super K,? super V,? extends Stream<? extends R>> mapper)` Returns a stream where the key-component of this stream has been replaced by the result of applying the specified mapping function to the entry.
`<R> MapStream<R,V>`	`flatMapKey(Function<? super K,? extends Stream<? extends R>> mapper)` Returns a stream where the key-component of this stream has been replaced by the result of applying the specified mapping function to the entry.
`DoubleStream`	`flatMapToDouble(BiFunction<? super K,? super V,? extends DoubleStream> mapper)` Returns an `DoubleStream` consisting of the results of replacing each key-value pair of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`DoubleStream`	`flatMapToDouble(Function<? super Map.Entry<K,V>,? extends DoubleStream> mapper)` Returns an `DoubleStream` consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`IntStream`	`flatMapToInt(BiFunction<? super K,? super V,? extends IntStream> mapper)` Returns an `IntStream` consisting of the results of replacing each key-value pair of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`IntStream`	`flatMapToInt(Function<? super Map.Entry<K,V>,? extends IntStream> mapper)` Returns an `IntStream` consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`LongStream`	`flatMapToLong(BiFunction<? super K,? super V,? extends LongStream> mapper)` Returns an `LongStream` consisting of the results of replacing each key-value pair of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`LongStream`	`flatMapToLong(Function<? super Map.Entry<K,V>,? extends LongStream> mapper)` Returns an `LongStream` consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
`<R> MapStream<K,R>`	`flatMapValue(BiFunction<? super K,? super V,? extends Stream<? extends R>> mapper)` Returns a stream where the value-component of this stream has been replaced by the result of applying the specified mapping function to the entry.
`<R> MapStream<K,R>`	`flatMapValue(Function<? super V,? extends Stream<? extends R>> mapper)` Returns a stream where the value-component of this stream has been replaced by the result of applying the specified mapping function to the entry.
`static <K,V> MapStream<V,K>`	`flip(MapStream<K,V> original)` Produces a new MapStream by flipping the specified one so that keys become values and values become keys.
`void`	`forEach(BiConsumer<? super K,? super V> action)` Performs an action for each key-value pair of this stream.
`void`	`forEach(Consumer<? super Map.Entry<K,V>> action)` Performs an action for each element of this stream.
`void`	`forEachOrdered(BiConsumer<? super K,? super V> action)` Performs an action for each key-value pair of this stream, in the encounter order of the stream if the stream has a defined encounter order.
`void`	`forEachOrdered(Consumer<? super Map.Entry<K,V>> action)` Performs an action for each element of this stream, in the encounter order of the stream if the stream has a defined encounter order.
`static <K,V> MapStream<K,V>`	`fromKeys(Stream<K> keys, Function<K,V> valueFromKey)` Constructs a new `MapStream` by wrapping a key-stream and calculating the corresponding values using the supplied function.
`static <E,K,V> MapStream<K,V>`	`fromStream(Stream<E> stream, Function<E,K> keyMapper, Function<E,V> valueMapper)` Constructs a new `MapStream` by wrapping a stream of objects and calculating both keys and values using the supplied functions.
`static <K,V> MapStream<K,V>`	`fromValues(Stream<V> values, Function<V,K> keyFromValue)` Constructs a new `MapStream` by wrapping a value-stream and calculating the corresponding keys using the supplied function.
`<K2> MapStream<K2,List<V>>`	`groupingBy(Function<V,K2> grouper)` Returns a new `MapStream` where the key component is calculated by applying the specified grouper function to the values of this stream and the value is a stream consisting of all the entries that produced the same key.
`boolean`	`isParallel()` Returns whether this stream, if a terminal operation were to be executed, would execute in parallel.
`Iterator<Map.Entry<K,V>>`	`iterator()` Returns an iterator for the elements of this stream.
`Stream<K>`	`keys()` Returns a stream of only the keys in this `MapStream`.
`MapStream<K,V>`	`limit(long maxSize)` Returns a stream consisting of the elements of this stream, truncated to be no longer than `maxSize` in length.
`<R> Stream<R>`	`map(BiFunction<? super K,? super V,? extends R> mapper)` Returns a stream consisting of the results of applying the given function to the elements of this stream.
`<R> Stream<R>`	`map(Function<? super Map.Entry<K,V>,? extends R> mapper)` Returns a stream consisting of the results of applying the given function to the elements of this stream.
`<R> MapStream<R,V>`	`mapKey(BiFunction<? super K,? super V,? extends R> mapper)` Returns a stream consisting of the results of applying the given function to the key-component of this stream.
`<R> MapStream<R,V>`	`mapKey(Function<? super K,? extends R> mapper)` Returns a stream consisting of the results of applying the given function to the key-component of this stream.
`DoubleStream`	`mapToDouble(ToDoubleBiFunction<? super K,? super V> mapper)` Returns a `DoubleStream` consisting of the results of applying the given function to the elements of this stream.
`DoubleStream`	`mapToDouble(ToDoubleFunction<? super Map.Entry<K,V>> mapper)` Returns a `DoubleStream` consisting of the results of applying the given function to the elements of this stream.
`IntStream`	`mapToInt(ToIntBiFunction<? super K,? super V> mapper)` Returns an `IntStream` consisting of the results of applying the given function to the elements of this stream.
`IntStream`	`mapToInt(ToIntFunction<? super Map.Entry<K,V>> mapper)` Returns an `IntStream` consisting of the results of applying the given function to the elements of this stream.
`LongStream`	`mapToLong(ToLongBiFunction<? super K,? super V> mapper)` Returns a `LongStream` consisting of the results of applying the given function to the elements of this stream.
`LongStream`	`mapToLong(ToLongFunction<? super Map.Entry<K,V>> mapper)` Returns a `LongStream` consisting of the results of applying the given function to the elements of this stream.
`<R> MapStream<K,R>`	`mapValue(BiFunction<? super K,? super V,? extends R> mapper)` Returns a stream consisting of the results of applying the given function to the value-component of this stream.
`<R> MapStream<K,R>`	`mapValue(Function<? super V,? extends R> mapper)` Returns a stream consisting of the results of applying the given function to the value-component of this stream.
`Optional<Map.Entry<K,V>>`	`max(Comparator<? super Map.Entry<K,V>> comparator)` Returns the maximum element of this stream according to the provided `Comparator`.
`Optional<Map.Entry<K,V>>`	`maxByKey(Comparator<K> comparator)` Returns the maximum element of this stream according to the provided `Comparator` applied to the key-components of this stream.
`Optional<Map.Entry<K,V>>`	`maxByValue(Comparator<V> comparator)` Returns the maximum element of this stream according to the provided `Comparator` applied to the value-components of this stream.
`Optional<Map.Entry<K,V>>`	`min(Comparator<? super Map.Entry<K,V>> comparator)` Returns the minimum element of this stream according to the provided `Comparator`.
`Optional<Map.Entry<K,V>>`	`minByKey(Comparator<K> comparator)` Returns the minimum element of this stream according to the provided `Comparator` applied to the key-components of this stream.
`Optional<Map.Entry<K,V>>`	`minByValue(Comparator<V> comparator)` Returns the minimum element of this stream according to the provided `Comparator` applied to the value-components of this stream.
`boolean`	`noneMatch(BiPredicate<? super K,? super V> predicate)` Returns whether no key-value pairs of this stream match the provided predicate.
`boolean`	`noneMatch(Predicate<? super Map.Entry<K,V>> predicate)` Returns whether no elements of this stream match the provided predicate.
`static <K,V> MapStream<K,V>`	`of(Map.Entry<K,V>... entries)` Constructs a new `MapStream` from an array of entries.
`static <K,V> MapStream<K,V>`	`of(Map.Entry<K,V> entry)` Constructs a new `MapStream` from a single entry.
`static <K,V> MapStream<K,V>`	`of(Map<K,V> map)` Constructs a new `MapStream` from a map of key-value pairs.
`static <K,V> MapStream<K,V>`	`of(Stream<Map.Entry<K,V>> stream)` Constructs a new `MapStream` by wrapping a key-value pair stream.
`MapStream<K,V>`	`onClose(Runnable closeHandler)` Returns an equivalent stream with an additional close handler.
`MapStream<K,V>`	`parallel()` Returns an equivalent stream that is parallel.
`MapStream<K,V>`	`peek(BiConsumer<? super K,? super V> action)` Returns a stream consisting of the key-value pairs of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.
`MapStream<K,V>`	`peek(Consumer<? super Map.Entry<K,V>> action)` Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.
`Optional<Map.Entry<K,V>>`	`reduce(BinaryOperator<Map.Entry<K,V>> accumulator)` Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an `Optional` describing the reduced value, if any.
`Map.Entry<K,V>`	`reduce(Map.Entry<K,V> identity, BinaryOperator<Map.Entry<K,V>> accumulator)` Performs a reduction on the elements of this stream, using the provided identity value and an associative accumulation function, and returns the reduced value.
`<U> U`	`reduce(U identity, BiFunction<U,? super Map.Entry<K,V>,U> accumulator, BinaryOperator<U> combiner)` Performs a reduction on the elements of this stream, using the provided identity, accumulation and combining functions.
`MapStream<K,V>`	`sequential()` Returns an equivalent stream that is sequential.
`MapStream<K,V>`	`skip(long n)` Returns a stream consisting of the remaining elements of this stream after discarding the first `n` elements of the stream.
`MapStream<K,V>`	`sorted()` Returns a stream consisting of the elements of this stream, sorted according to natural order.
`MapStream<K,V>`	`sorted(Comparator<? super Map.Entry<K,V>> comparator)` Returns a stream consisting of the elements of this stream, sorted according to the provided `Comparator`.
`MapStream<K,V>`	`sortedByKey(Comparator<K> comparator)` Returns a stream consisting of the elements of this stream, sorted according to the provided `Comparator` applied to the keys of the entries.
`MapStream<K,V>`	`sortedByValue(Comparator<V> comparator)` Returns a stream consisting of the elements of this stream, sorted according to the provided `Comparator` applied to the values of the entries.
`Spliterator<Map.Entry<K,V>>`	`spliterator()` Returns a spliterator for the elements of this stream.
`static <T> BinaryOperator<T>`	`throwingMerger()` Returns a merge function, suitable for use in `Map.merge()` or `toMap()`, which always throws `IllegalStateException`.
`Object[]`	`toArray()` Returns an array containing the elements of this stream.
`<A> A[]`	`toArray(IntFunction<A[]> generator)` Returns an array containing the elements of this stream, using the provided `generator` function to allocate the returned array, as well as any additional arrays that might be required for a partitioned execution or for resizing.
`Map<K,V>`	`toConcurrentMap()` Accumulates all key-value pairs of this `MapStream` into a `ConcurrentMap`.
`Map<K,V>`	`toConcurrentMap(BinaryOperator<V> mergeFunction)` Accumulates all key-value pairs of this `MapStream` into a `ConcurrentMap`.
`ConcurrentNavigableMap<K,V>`	`toConcurrentNavigableMap()` Accumulates all key-value pairs of this `MapStream` into a `ConcurrentNavigableMap`.
`ConcurrentNavigableMap<K,V>`	`toConcurrentNavigableMap(BinaryOperator<V> mergeFunction)` Accumulates all key-value pairs of this `MapStream` into a `ConcurrentNavigableMap`.
`ConcurrentNavigableMap<K,V>`	`toConcurrentNavigableMap(Comparator<K> keyComparator, BinaryOperator<V> mergeFunction)` Accumulates all key-value pairs of this `MapStream` into a `ConcurrentNavigableMap`, sorting the entries by applying the specified comparator to the keys of the stream.
`ConcurrentNavigableMap<K,V>`	`toConcurrentNavigableMapByKey(Comparator<K> keyComparator)` Accumulates all key-value pairs of this `MapStream` into a `ConcurrentNavigableMap`, sorting the entries by applying the specified comparator to the keys of the stream.
`List<Map.Entry<K,V>>`	`toList()` Accumulates all entries of this `MapStream` into a `List`.
`Map<K,V>`	`toMap()` Accumulates all key-value pairs of this `MapStream` into a `Map`.
`Map<K,V>`	`toMap(BinaryOperator<V> mergeFunction)` Accumulates all key-value pairs of this `MapStream` into a `Map`.
`SortedMap<K,V>`	`toSortedMap()` Accumulates all key-value pairs of this `MapStream` into a `SortedMap`.
`SortedMap<K,V>`	`toSortedMap(BinaryOperator<V> mergeFunction)` Accumulates all key-value pairs of this `MapStream` into a `SortedMap`.
`SortedMap<K,V>`	`toSortedMap(Comparator<K> keyComparator, BinaryOperator<V> mergeFunction)` Accumulates all key-value pairs of this `MapStream` into a `SortedMap`, sorting the entries by applying the specified comparator to the keys of the stream.
`SortedMap<K,V>`	`toSortedMapByKey(Comparator<K> keyComparator)` Accumulates all key-value pairs of this `MapStream` into a `SortedMap`, sorting the entries by applying the specified comparator to the keys of the stream.
`MapStream<K,V>`	`unordered()` Returns an equivalent stream that is unordered.
`Stream<V>`	`values()` Returns a stream of only the values in this `MapStream`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.stream.Stream
builder, concat, generate, iterate

- Method Detail
  - of
```
public static <K,V> MapStream<K,V> of(Map.Entry<K,V> entry)
```
    Constructs a new MapStream from a single entry.
    
    Specified by:
    
    of in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    K - key type
    
    V - value type
    
    Parameters:
    
    entry - the entry
    
    Returns:
    
    created MapStream
  - of
```
@SafeVarargs
public static <K,V> MapStream<K,V> of(Map.Entry<K,V>... entries)
```
    Constructs a new MapStream from an array of entries.
    
    Specified by:
    
    of in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    K - key type
    
    V - value type
    
    Parameters:
    
    entries - elements to stream over
    
    Returns:
    
    created MapStream
  - of
```
public static <K,V> MapStream<K,V> of(Map<K,V> map)
```
    Constructs a new MapStream from a map of key-value pairs. The map will not be affected.
    This is equivalent to writing: MapStream.of(map.entrySet().stream());
    
    Specified by:
    
    of in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    K - key type
    
    V - value type
    
    Parameters:
    
    map - elements to stream over
    
    Returns:
    
    created MapStream
  - of
```
public static <K,V> MapStream<K,V> of(Stream<Map.Entry<K,V>> stream)
```
    Constructs a new MapStream by wrapping a key-value pair stream. The provided stream will be wrapped in this stream. After this method is called, no more changes should be done to the stream!
    
    Specified by:
    
    of in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    K - key type
    
    V - value type
    
    Parameters:
    
    stream - stream to wrap
    
    Returns:
    
    created MapStream
  - fromKeys
```
public static <K,V> MapStream<K,V> fromKeys(Stream<K> keys,
                                            Function<K,V> valueFromKey)
```
    Constructs a new MapStream by wrapping a key-stream and calculating the corresponding values using the supplied function.
    
    Type Parameters:
    
    K - key type
    
    V - value type
    
    Parameters:
    
    keys - stream of keys to wrap
    
    valueFromKey - method for calculating values from keys
    
    Returns:
    
    created MapStream
  - fromValues
```
public static <K,V> MapStream<K,V> fromValues(Stream<V> values,
                                              Function<V,K> keyFromValue)
```
    Constructs a new MapStream by wrapping a value-stream and calculating the corresponding keys using the supplied function.
    
    Type Parameters:
    
    K - key type
    
    V - value type
    
    Parameters:
    
    values - stream of values to wrap
    
    keyFromValue - method for calculating keys from values
    
    Returns:
    
    created MapStream
  - fromStream
```
public static <E,K,V> MapStream<K,V> fromStream(Stream<E> stream,
                                                Function<E,K> keyMapper,
                                                Function<E,V> valueMapper)
```
    Constructs a new MapStream by wrapping a stream of objects and calculating both keys and values using the supplied functions.
    
    Type Parameters:
    
    E - original stream type
    
    K - key type
    
    V - value type
    
    Parameters:
    
    stream - original stream
    
    keyMapper - method for calculating keys
    
    valueMapper - method for calculating values
    
    Returns:
    
    created MapStream
  - empty
```
public static <K,V> MapStream<K,V> empty()
```
    Constructs an empty MapStream.
    
    Specified by:
    
    empty in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    K - key type
    
    V - value type
    
    Returns:
    
    an empty MapStream
  - flip
```
public static <K,V> MapStream<V,K> flip(MapStream<K,V> original)
```
    Produces a new MapStream by flipping the specified one so that keys become values and values become keys. This will consume the supplied stream.
    
    Type Parameters:
    
    K - original key type
    
    V - original value type
    
    Parameters:
    
    original - original MapStream
    
    Returns:
    
    new MapStream with keys and values flipped
  - filter
```
public MapStream<K,V> filter(Predicate<? super Map.Entry<K,V>> predicate)
```
    Returns a stream consisting of the elements of this stream that match the given predicate.
    This is an intermediate operation.
    
    Specified by:
    
    filter in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to each element to determine if it should be included
    
    Returns:
    
    the new stream
  - filter
```
public MapStream<K,V> filter(BiPredicate<? super K,? super V> predicate)
```
    Returns a stream consisting of the elements of this stream that match the given predicate.
    This is an intermediate operation.
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to each key-value pair to determine if it should be included
    
    Returns:
    
    the new stream
  - filterKey
```
public MapStream<K,V> filterKey(Predicate<? super K> predicate)
```
    Returns a stream consisting of the elements of this stream where the key component matches the given predicate.
    This is an intermediate operation.
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to each key to determine if the entry should be included
    
    Returns:
    
    the new stream
  - filterValue
```
public MapStream<K,V> filterValue(Predicate<? super V> predicate)
```
    Returns a stream consisting of the elements of this stream where the value component matches the given predicate.
    This is an intermediate operation.
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to each value to determine if the entry should be included
    
    Returns:
    
    the new stream
  - map
```
public <R> Stream<R> map(Function<? super Map.Entry<K,V>,? extends R> mapper)
```
    Returns a stream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Specified by:
    
    map in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element
    
    Returns:
    
    the new stream
  - map
```
public <R> Stream<R> map(BiFunction<? super K,? super V,? extends R> mapper)
```
    Returns a stream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair
    
    Returns:
    
    the new stream
  - mapKey
```
public <R> MapStream<R,V> mapKey(BiFunction<? super K,? super V,? extends R> mapper)
```
    Returns a stream consisting of the results of applying the given function to the key-component of this stream.
    This is an intermediate operation.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key in the stream
    
    Returns:
    
    the new stream
  - mapKey
```
public <R> MapStream<R,V> mapKey(Function<? super K,? extends R> mapper)
```
    Returns a stream consisting of the results of applying the given function to the key-component of this stream.
    This is an intermediate operation.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key in the stream
    
    Returns:
    
    the new stream
  - mapValue
```
public <R> MapStream<K,R> mapValue(BiFunction<? super K,? super V,? extends R> mapper)
```
    Returns a stream consisting of the results of applying the given function to the value-component of this stream.
    This is an intermediate operation.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each value in the stream
    
    Returns:
    
    the new stream
  - mapValue
```
public <R> MapStream<K,R> mapValue(Function<? super V,? extends R> mapper)
```
    Returns a stream consisting of the results of applying the given function to the value-component of this stream.
    This is an intermediate operation.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each value in the stream
    
    Returns:
    
    the new stream
  - mapToInt
```
public IntStream mapToInt(ToIntFunction<? super Map.Entry<K,V>> mapper)
```
    Returns an IntStream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Specified by:
    
    mapToInt in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element
    
    Returns:
    
    the new stream
  - mapToInt
```
public IntStream mapToInt(ToIntBiFunction<? super K,? super V> mapper)
```
    Returns an IntStream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element
    
    Returns:
    
    the new stream
  - mapToLong
```
public LongStream mapToLong(ToLongFunction<? super Map.Entry<K,V>> mapper)
```
    Returns a LongStream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Specified by:
    
    mapToLong in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element
    
    Returns:
    
    the new stream
  - mapToLong
```
public LongStream mapToLong(ToLongBiFunction<? super K,? super V> mapper)
```
    Returns a LongStream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element
    
    Returns:
    
    the new stream
  - mapToDouble
```
public DoubleStream mapToDouble(ToDoubleFunction<? super Map.Entry<K,V>> mapper)
```
    Returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Specified by:
    
    mapToDouble in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element
    
    Returns:
    
    the new stream
  - mapToDouble
```
public DoubleStream mapToDouble(ToDoubleBiFunction<? super K,? super V> mapper)
```
    Returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.
    This is an intermediate operation.
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element
    
    Returns:
    
    the new stream
  - flatMap
```
public <R> Stream<R> flatMap(Function<? super Map.Entry<K,V>,? extends Stream<? extends R>> mapper)
```
    Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    The flatMap() operation has the effect of applying a one-to-many transformation to the elements of the stream, and then flattening the resulting elements into a new stream.
    Examples.
    If orders is a stream of purchase orders, and each purchase order contains a collection of line items, then the following produces a stream containing all the line items in all the orders:
```
     orders.flatMap(order -> order.getLineItems().stream())...
 
```
    If path is the path to a file, then the following produces a stream of the words contained in that file:
```
     Stream<String> lines = Files.lines(path, StandardCharsets.UTF_8);
     Stream<String> words = lines.flatMap(line -> Stream.of(line.split(" +")));
 
```
    The mapper function passed to flatMap splits a line, using a simple regular expression, into an array of words, and then creates a stream of words from that array.
    Specified by:
    
    flatMap in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element which produces a stream of new elements
    
    Returns:
    
    the new stream
  - flatMap
```
public <R> Stream<R> flatMap(BiFunction<? super K,? super V,? extends Stream<? extends R>> mapper)
```
    Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    The flatMap() operation has the effect of applying a one-to-many transformation to the elements of the stream, and then flattening the resulting elements into a new stream.
    Examples.
    If orders is a stream of purchase orders, and each purchase order contains a collection of line items, then the following produces a stream containing all the line items in all the orders:
```
     orders.flatMap(order -> order.getLineItems().stream())...
 
```
    If path is the path to a file, then the following produces a stream of the words contained in that file:
```
     Stream<String> lines = Files.lines(path, StandardCharsets.UTF_8);
     Stream<String> words = lines.flatMap(line -> Stream.of(line.split(" +")));
 
```
    The mapper function passed to flatMap splits a line, using a simple regular expression, into an array of words, and then creates a stream of words from that array.
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element which produces a stream of new elements
    
    Returns:
    
    the new stream
  - flatMapKey
```
public <R> MapStream<R,V> flatMapKey(BiFunction<? super K,? super V,? extends Stream<? extends R>> mapper)
```
    Returns a stream where the key-component of this stream has been replaced by the result of applying the specified mapping function to the entry. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    The flatMap() operation has the effect of applying a one-to-many transformation to the elements of the stream, and then flattening the resulting elements into a new stream.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair which produces a stream of new keys
    
    Returns:
    
    the new stream
  - flatMapKey
```
public <R> MapStream<R,V> flatMapKey(Function<? super K,? extends Stream<? extends R>> mapper)
```
    Returns a stream where the key-component of this stream has been replaced by the result of applying the specified mapping function to the entry. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    The flatMap() operation has the effect of applying a one-to-many transformation to the elements of the stream, and then flattening the resulting elements into a new stream.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair which produces a stream of new keys
    
    Returns:
    
    the new stream
  - flatMapValue
```
public <R> MapStream<K,R> flatMapValue(BiFunction<? super K,? super V,? extends Stream<? extends R>> mapper)
```
    Returns a stream where the value-component of this stream has been replaced by the result of applying the specified mapping function to the entry. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    The flatMap() operation has the effect of applying a one-to-many transformation to the elements of the stream, and then flattening the resulting elements into a new stream.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair which produces a stream of new values
    
    Returns:
    
    the new stream
  - flatMapValue
```
public <R> MapStream<K,R> flatMapValue(Function<? super V,? extends Stream<? extends R>> mapper)
```
    Returns a stream where the value-component of this stream has been replaced by the result of applying the specified mapping function to the entry. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    The flatMap() operation has the effect of applying a one-to-many transformation to the elements of the stream, and then flattening the resulting elements into a new stream.
    
    Type Parameters:
    
    R - the element type of the new stream
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair which produces a stream of new values
    
    Returns:
    
    the new stream
  - flatMapToInt
```
public IntStream flatMapToInt(Function<? super Map.Entry<K,V>,? extends IntStream> mapper)
```
    Returns an IntStream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    
    Specified by:
    
    flatMapToInt in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element which produces a stream of new elements
    
    Returns:
    
    the new stream
    
    See Also:
    
    flatMap(Function)
  - flatMapToInt
```
public IntStream flatMapToInt(BiFunction<? super K,? super V,? extends IntStream> mapper)
```
    Returns an IntStream consisting of the results of replacing each key-value pair of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair which produces a stream of new elements
    
    Returns:
    
    the new stream
    
    See Also:
    
    flatMap(Function)
  - flatMapToLong
```
public LongStream flatMapToLong(Function<? super Map.Entry<K,V>,? extends LongStream> mapper)
```
    Returns an LongStream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    
    Specified by:
    
    flatMapToLong in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element which produces a stream of new elements
    
    Returns:
    
    the new stream
    
    See Also:
    
    flatMap(Function)
  - flatMapToLong
```
public LongStream flatMapToLong(BiFunction<? super K,? super V,? extends LongStream> mapper)
```
    Returns an LongStream consisting of the results of replacing each key-value pair of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair which produces a stream of new elements
    
    Returns:
    
    the new stream
    
    See Also:
    
    flatMap(Function)
  - flatMapToDouble
```
public DoubleStream flatMapToDouble(Function<? super Map.Entry<K,V>,? extends DoubleStream> mapper)
```
    Returns an DoubleStream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have placed been into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    
    Specified by:
    
    flatMapToDouble in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each element which produces a stream of new elements
    
    Returns:
    
    the new stream
    
    See Also:
    
    flatMap(Function)
  - flatMapToDouble
```
public DoubleStream flatMapToDouble(BiFunction<? super K,? super V,? extends DoubleStream> mapper)
```
    Returns an DoubleStream consisting of the results of replacing each key-value pair of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have placed been into this stream. (If a mapped stream is null an empty stream is used, instead.)
    This is an intermediate operation.
    
    Parameters:
    
    mapper - a non-interfering, stateless function to apply to each key-value pair which produces a stream of new elements
    
    Returns:
    
    the new stream
    
    See Also:
    
    flatMap(Function)
  - keys
```
public Stream<K> keys()
```
    Returns a stream of only the keys in this MapStream.
    This is an intermediate operation.
    
    Returns:
    
    a new stream of all keys
  - values
```
public Stream<V> values()
```
    Returns a stream of only the values in this MapStream.
    This is an intermediate operation.
    
    Returns:
    
    a new stream of all values
  - distinct
```
public MapStream<K,V> distinct()
```
    Returns a stream consisting of the distinct elements (according to Object.equals(Object)) of this stream.
    For ordered streams, the selection of distinct elements is stable (for duplicated elements, the element appearing first in the encounter order is preserved.) For unordered streams, no stability guarantees are made.
    This is a stateful intermediate operation.
    Preserving stability for distinct() in parallel pipelines is relatively expensive (requires that the operation act as a full barrier, with substantial buffering overhead), and stability is often not needed. Using an unordered stream source (such as Stream.generate(Supplier)) or removing the ordering constraint with unordered() may result in significantly more efficient execution for distinct() in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with distinct() in parallel pipelines, switching to sequential execution with sequential() may improve performance.
    
    Specified by:
    
    distinct in interface Stream<Map.Entry<K,V>>
    
    Returns:
    
    the new stream
  - distinctKeys
```
public MapStream<K,V> distinctKeys()
```
    Returns a stream consisting of the distinct elements (according to Object.equals(Object)) of this stream based on the key only. If the same key is encountered multiple times, only the first occurence will be allowed to pass.
    This is a stateful intermediate operation.
    
    Returns:
    
    the new stream
  - distinctValues
```
public MapStream<K,V> distinctValues()
```
    Returns a stream consisting of the distinct elements (according to Object.equals(Object)) of this stream based on the value only. If the same value is encountered multiple times, only the first occurence will be allowed to pass.
    This is a stateful intermediate operation.
    
    Returns:
    
    the new stream
  - distinctKeys
```
public MapStream<K,V> distinctKeys(BinaryOperator<V> merger)
```
    Returns a stream consisting of the distinct elements (according to Object.equals(Object)) of this stream based on the key only. If the same key is encountered multiple times, the specified value merger will be used to determine which value can pass.
    This operation will consume the wrapped stream and produce a new one. The complexity of this operation is therefore O(n).
    This is a stateful intermediate operation.
    
    Parameters:
    
    merger - the merging operation to use
    
    Returns:
    
    the new stream
  - distinctValues
```
public MapStream<K,V> distinctValues(BinaryOperator<K> merger)
```
    Returns a stream consisting of the distinct elements (according to Object.equals(Object)) of this stream based on the value only. If the same value is encountered multiple times, the specified key merger will be used to determine which value can pass.
    This operation will consume the wrapped stream and produce a new one. The complexity of this operation is therefore O(n).
    This is a stateful intermediate operation.
    
    Parameters:
    
    merger - the merging operation to use
    
    Returns:
    
    the new stream
  - sorted
```
public MapStream<K,V> sorted()
```
    Returns a stream consisting of the elements of this stream, sorted according to natural order. If the elements of this stream are not Comparable, a java.lang.ClassCastException may be thrown when the terminal operation is executed.
    For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
    This is a stateful intermediate operation.
    
    Specified by:
    
    sorted in interface Stream<Map.Entry<K,V>>
    
    Returns:
    
    the new stream
  - sorted
```
public MapStream<K,V> sorted(Comparator<? super Map.Entry<K,V>> comparator)
```
    Returns a stream consisting of the elements of this stream, sorted according to the provided Comparator.
    For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
    This is a stateful intermediate operation.
    
    Specified by:
    
    sorted in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to be used to compare stream elements
    
    Returns:
    
    the new stream
  - sortedByKey
```
public MapStream<K,V> sortedByKey(Comparator<K> comparator)
```
    Returns a stream consisting of the elements of this stream, sorted according to the provided Comparator applied to the keys of the entries.
    For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
    This is a stateful intermediate operation.
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to be used to compare entity keys
    
    Returns:
    
    the new stream
  - sortedByValue
```
public MapStream<K,V> sortedByValue(Comparator<V> comparator)
```
    Returns a stream consisting of the elements of this stream, sorted according to the provided Comparator applied to the values of the entries.
    For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
    This is a stateful intermediate operation.
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to be used to compare entity values
    
    Returns:
    
    the new stream
  - peek
```
public MapStream<K,V> peek(Consumer<? super Map.Entry<K,V>> action)
```
    Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.
    This is an intermediate operation.
    For parallel stream pipelines, the action may be called at whatever time and in whatever thread the element is made available by the upstream operation. If the action modifies shared state, it is responsible for providing the required synchronization.
    This method exists mainly to support debugging, where you want to see the elements as they flow past a certain point in a pipeline:
```
     Stream.of("one", "two", "three", "four")
         .filter(e -> e.length() > 3)
         .peek(e -> System.out.println("Filtered value: " + e))
         .map(String::toUpperCase)
         .peek(e -> System.out.println("Mapped value: " + e))
         .collect(Collectors.toList());
 
```
    Specified by:
    
    peek in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    action - a non-interfering action to perform on the elements as they are consumed from the stream
    
    Returns:
    
    the new stream
  - peek
```
public MapStream<K,V> peek(BiConsumer<? super K,? super V> action)
```
    Returns a stream consisting of the key-value pairs of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.
    This is an intermediate operation.
    For parallel stream pipelines, the action may be called at whatever time and in whatever thread the element is made available by the upstream operation. If the action modifies shared state, it is responsible for providing the required synchronization.
    This method exists mainly to support debugging, where you want to see the elements as they flow past a certain point in a pipeline:
```
     Stream.of("one", "two", "three", "four")
         .filter(e -> e.length() > 3)
         .peek(e -> System.out.println("Filtered value: " + e))
         .map(String::toUpperCase)
         .peek(e -> System.out.println("Mapped value: " + e))
         .collect(Collectors.toList());
 
```
    Parameters:
    
    action - a non-interfering action to perform on the key-value pairs as they are consumed from the stream
    
    Returns:
    
    the new stream
  - limit
```
public MapStream<K,V> limit(long maxSize)
```
    Returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length.
    This is a short-circuiting stateful intermediate operation.
    While limit() is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, especially for large values of maxSize, since limit(n) is constrained to return not just any n elements, but the first n elements in the encounter order. Using an unordered stream source (such as Stream.generate(Supplier)) or removing the ordering constraint with unordered() may result in significant speedups of limit() in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with limit() in parallel pipelines, switching to sequential execution with sequential() may improve performance.
    
    Specified by:
    
    limit in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    maxSize - the number of elements the stream should be limited to
    
    Returns:
    
    the new stream
    
    Throws:
    
    IllegalArgumentException - if maxSize is negative
  - skip
```
public MapStream<K,V> skip(long n)
```
    Returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned.
    This is a stateful intermediate operation.
    While skip() is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, especially for large values of n, since skip(n) is constrained to skip not just any n elements, but the first n elements in the encounter order. Using an unordered stream source (such as Stream.generate(Supplier)) or removing the ordering constraint with unordered() may result in significant speedups of skip() in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with skip() in parallel pipelines, switching to sequential execution with sequential() may improve performance.
    
    Specified by:
    
    skip in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    n - the number of leading elements to skip
    
    Returns:
    
    the new stream
    
    Throws:
    
    IllegalArgumentException - if n is negative
  - forEach
```
public void forEach(Consumer<? super Map.Entry<K,V>> action)
```
    Performs an action for each element of this stream.
    This is a terminal operation.
    The behavior of this operation is explicitly nondeterministic. For parallel stream pipelines, this operation does not guarantee to respect the encounter order of the stream, as doing so would sacrifice the benefit of parallelism. For any given element, the action may be performed at whatever time and in whatever thread the library chooses. If the action accesses shared state, it is responsible for providing the required synchronization.
    
    Specified by:
    
    forEach in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    action - a non-interfering action to perform on the elements
  - forEach
```
public void forEach(BiConsumer<? super K,? super V> action)
```
    Performs an action for each key-value pair of this stream.
    This is a terminal operation.
    The behavior of this operation is explicitly nondeterministic. For parallel stream pipelines, this operation does not guarantee to respect the encounter order of the stream, as doing so would sacrifice the benefit of parallelism. For any given element, the action may be performed at whatever time and in whatever thread the library chooses. If the action accesses shared state, it is responsible for providing the required synchronization.
    
    Parameters:
    
    action - a non-interfering action to perform on the key-value pairs
  - forEachOrdered
```
public void forEachOrdered(Consumer<? super Map.Entry<K,V>> action)
```
    Performs an action for each element of this stream, in the encounter order of the stream if the stream has a defined encounter order.
    This is a terminal operation.
    This operation processes the elements one at a time, in encounter order if one exists. Performing the action for one element happens-before performing the action for subsequent elements, but for any given element, the action may be performed in whatever thread the library chooses.
    
    Specified by:
    
    forEachOrdered in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    action - a non-interfering action to perform on the elements
    
    See Also:
    
    forEach(Consumer)
  - forEachOrdered
```
public void forEachOrdered(BiConsumer<? super K,? super V> action)
```
    Performs an action for each key-value pair of this stream, in the encounter order of the stream if the stream has a defined encounter order.
    This is a terminal operation.
    This operation processes the key-value pairs one at a time, in encounter order if one exists. Performing the action for one element happens-before performing the action for subsequent key-value pairs, but for any given element, the action may be performed in whatever thread the library chooses.
    
    Parameters:
    
    action - a non-interfering action to perform on the key-value pairs
    
    See Also:
    
    forEach(Consumer)
  - toArray
```
public Object[] toArray()
```
    Returns an array containing the elements of this stream.
    This is a terminal operation.
    
    Specified by:
    
    toArray in interface Stream<Map.Entry<K,V>>
    
    Returns:
    
    an array containing the elements of this stream
  - toArray
```
public <A> A[] toArray(IntFunction<A[]> generator)
```
    Returns an array containing the elements of this stream, using the provided generator function to allocate the returned array, as well as any additional arrays that might be required for a partitioned execution or for resizing.
    This is a terminal operation.
    The generator function takes an integer, which is the size of the desired array, and produces an array of the desired size. This can be concisely expressed with an array constructor reference:
```
     Person[] men = people.stream()
                          .filter(p -> p.getGender() == MALE)
                          .toArray(Person[]::new);
 
```
    Specified by:
    
    toArray in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    A - the element type of the resulting array
    
    Parameters:
    
    generator - a function which produces a new array of the desired type and the provided length
    
    Returns:
    
    an array containing the elements in this stream
    
    Throws:
    
    ArrayStoreException - if the runtime type of the array returned from the array generator is not a supertype of the runtime type of every element in this stream
  - reduce
```
public Map.Entry<K,V> reduce(Map.Entry<K,V> identity,
                             BinaryOperator<Map.Entry<K,V>> accumulator)
```
    Performs a reduction on the elements of this stream, using the provided identity value and an associative accumulation function, and returns the reduced value. This is equivalent to:
```
     T result = identity;
     for (T element : this stream)
         result = accumulator.apply(result, element)
     return result;
 
```
    but is not constrained to execute sequentially.
    The identity value must be an identity for the accumulator function. This means that for all t, accumulator.apply(identity, t) is equal to t. The accumulator function must be an associative function.
    This is a terminal operation.
    Sum, min, max, average, and string concatenation are all special cases of reduction. Summing a stream of numbers can be expressed as:
```
     Integer sum = integers.reduce(0, (a, b) -> a+b);
 
```
    or:
```
     Integer sum = integers.reduce(0, Integer::sum);
 
```
    While this may seem a more roundabout way to perform an aggregation compared to simply mutating a running total in a loop, reduction operations parallelize more gracefully, without needing additional synchronization and with greatly reduced risk of data races.
    Specified by:
    
    reduce in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    identity - the identity value for the accumulating function
    
    accumulator - an associative, non-interfering stateless function for combining two values
    
    Returns:
    
    the result of the reduction
  - reduce
```
public Optional<Map.Entry<K,V>> reduce(BinaryOperator<Map.Entry<K,V>> accumulator)
```
    Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an Optional describing the reduced value, if any. This is equivalent to:
```
     boolean foundAny = false;
     T result = null;
     for (T element : this stream) {
         if (!foundAny) {
             foundAny = true;
             result = element;
         }
         else
             result = accumulator.apply(result, element);
     }
     return foundAny ? Optional.of(result) : Optional.empty();
 
```
    but is not constrained to execute sequentially.
    The accumulator function must be an associative function.
    This is a terminal operation.
    Specified by:
    
    reduce in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    accumulator - an associative, non-interfering, stateless function for combining two values
    
    Returns:
    
    an Optional describing the result of the reduction
    
    Throws:
    
    NullPointerException - if the result of the reduction is null
    
    See Also:
    
    Stream.reduce(Object, BinaryOperator), min(Comparator), max(Comparator)
  - reduce
```
public <U> U reduce(U identity,
                    BiFunction<U,? super Map.Entry<K,V>,U> accumulator,
                    BinaryOperator<U> combiner)
```
    Performs a reduction on the elements of this stream, using the provided identity, accumulation and combining functions. This is equivalent to:
```
     U result = identity;
     for (T element : this stream)
         result = accumulator.apply(result, element)
     return result;
 
```
    but is not constrained to execute sequentially.
    The identity value must be an identity for the combiner function. This means that for all u, combiner(identity, u) is equal to u. Additionally, the combiner function must be compatible with the accumulator function; for all u and t, the following must hold:
```
     combiner.apply(u, accumulator.apply(identity, t)) == accumulator.apply(u, t)
 
```
    This is a terminal operation.
    Many reductions using this form can be represented more simply by an explicit combination of map and reduce operations. The accumulator function acts as a fused mapper and accumulator, which can sometimes be more efficient than separate mapping and reduction, such as when knowing the previously reduced value allows you to avoid some computation.
    Specified by:
    
    reduce in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    U - the type of the result
    
    Parameters:
    
    identity - the identity value for the combiner function
    
    accumulator - an associative, non-interfering, stateless function for incorporating an additional element into a result
    
    combiner - an associative, non-interfering, stateless function for combining two values, which must be compatible with the accumulator function
    
    Returns:
    
    the result of the reduction
    
    See Also:
    
    reduce(BinaryOperator), Stream.reduce(Object, BinaryOperator)
  - collect
```
public <R> R collect(Supplier<R> supplier,
                     BiConsumer<R,? super Map.Entry<K,V>> accumulator,
                     BiConsumer<R,R> combiner)
```
    Performs a mutable reduction operation on the elements of this stream. A mutable reduction is one in which the reduced value is a mutable result container, such as an ArrayList, and elements are incorporated by updating the state of the result rather than by replacing the result. This produces a result equivalent to:
```
     R result = supplier.get();
     for (T element : this stream)
         accumulator.accept(result, element);
     return result;
 
```
    Like Stream.reduce(Object, BinaryOperator), collect operations can be parallelized without requiring additional synchronization.
    This is a terminal operation.
    There are many existing classes in the JDK whose signatures are well-suited for use with method references as arguments to collect(). For example, the following will accumulate strings into an ArrayList:
```
     List<String> asList = stringStream.collect(ArrayList::new, ArrayList::add,
                                                ArrayList::addAll);
 
```
    The following will take a stream of strings and concatenates them into a single string:
```
     String concat = stringStream.collect(StringBuilder::new, StringBuilder::append,
                                          StringBuilder::append)
                                 .toString();
 
```
    Specified by:
    
    collect in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    R - type of the result
    
    Parameters:
    
    supplier - a function that creates a new result container. For a parallel execution, this function may be called multiple times and must return a fresh value each time.
    
    accumulator - an associative, non-interfering, stateless function for incorporating an additional element into a result
    
    combiner - an associative, non-interfering, stateless function for combining two values, which must be compatible with the accumulator function
    
    Returns:
    
    the result of the reduction
  - collect
```
public <R,A> R collect(Collector<? super Map.Entry<K,V>,A,R> collector)
```
    Performs a mutable reduction operation on the elements of this stream using a Collector. A Collector encapsulates the functions used as arguments to collect(Supplier, BiConsumer, BiConsumer), allowing for reuse of collection strategies and composition of collect operations such as multiple-level grouping or partitioning.
    If the stream is parallel, and the Collector is concurrent, and either the stream is unordered or the collector is unordered, then a concurrent reduction will be performed (see Collector for details on concurrent reduction.)
    This is a terminal operation.
    When executed in parallel, multiple intermediate results may be instantiated, populated, and merged so as to maintain isolation of mutable data structures. Therefore, even when executed in parallel with non-thread-safe data structures (such as ArrayList), no additional synchronization is needed for a parallel reduction.
    The following will accumulate strings into an ArrayList:
```
     List<String> asList = stringStream.collect(Collectors.toList());
 
```
    The following will classify Person objects by city:
```
     Map<String, List<Person>> peopleByCity
         = personStream.collect(Collectors.groupingBy(Person::getCity));
 
```
    The following will classify Person objects by state and city, cascading two Collectors together:
```
     Map<String, Map<String, List<Person>>> peopleByStateAndCity
         = personStream.collect(Collectors.groupingBy(Person::getState,
                                                      Collectors.groupingBy(Person::getCity)));
 
```
    Specified by:
    
    collect in interface Stream<Map.Entry<K,V>>
    
    Type Parameters:
    
    R - the type of the result
    
    A - the intermediate accumulation type of the Collector
    
    Parameters:
    
    collector - the Collector describing the reduction
    
    Returns:
    
    the result of the reduction
    
    See Also:
    
    collect(Supplier, BiConsumer, BiConsumer), Collectors
  - groupingBy
```
public <K2> MapStream<K2,List<V>> groupingBy(Function<V,K2> grouper)
```
    Returns a new MapStream where the key component is calculated by applying the specified grouper function to the values of this stream and the value is a stream consisting of all the entries that produced the same key.
    This is a stateful intermediate operation.
    
    Type Parameters:
    
    K2 - the type of the new key
    
    Parameters:
    
    grouper - the function to use for grouping entries
    
    Returns:
    
    the new stream
  - min
```
public Optional<Map.Entry<K,V>> min(Comparator<? super Map.Entry<K,V>> comparator)
```
    Returns the minimum element of this stream according to the provided Comparator. This is a special case of a reduction.
    This is a terminal operation.
    
    Specified by:
    
    min in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to compare elements of this stream
    
    Returns:
    
    an Optional describing the minimum element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the minimum element is null
  - minByKey
```
public Optional<Map.Entry<K,V>> minByKey(Comparator<K> comparator)
```
    Returns the minimum element of this stream according to the provided Comparator applied to the key-components of this stream. This is a special case of a reduction.
    This is a terminal operation.
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to compare keys of this stream
    
    Returns:
    
    an Optional describing the minimum element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the minimum element is null
  - minByValue
```
public Optional<Map.Entry<K,V>> minByValue(Comparator<V> comparator)
```
    Returns the minimum element of this stream according to the provided Comparator applied to the value-components of this stream. This is a special case of a reduction.
    This is a terminal operation.
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to compare values of this stream
    
    Returns:
    
    an Optional describing the minimum element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the minimum element is null
  - max
```
public Optional<Map.Entry<K,V>> max(Comparator<? super Map.Entry<K,V>> comparator)
```
    Returns the maximum element of this stream according to the provided Comparator. This is a special case of a reduction.
    This is a terminal operation.
    
    Specified by:
    
    max in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to compare elements of this stream
    
    Returns:
    
    an Optional describing the maximum element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the maximum element is null
  - maxByKey
```
public Optional<Map.Entry<K,V>> maxByKey(Comparator<K> comparator)
```
    Returns the maximum element of this stream according to the provided Comparator applied to the key-components of this stream. This is a special case of a reduction.
    This is a terminal operation.
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to compare keys of this stream
    
    Returns:
    
    an Optional describing the maximum element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the maximum element is null
  - maxByValue
```
public Optional<Map.Entry<K,V>> maxByValue(Comparator<V> comparator)
```
    Returns the maximum element of this stream according to the provided Comparator applied to the value-components of this stream. This is a special case of a reduction.
    This is a terminal operation.
    
    Parameters:
    
    comparator - a non-interfering, stateless Comparator to compare values of this stream
    
    Returns:
    
    an Optional describing the maximum element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the maximum element is null
  - count
```
public long count()
```
    Returns the count of elements in this stream. This is a special case of a reduction and is equivalent to:
```
     return mapToLong(e -> 1L).sum();
 
```
    This is a terminal operation.
    Specified by:
    
    count in interface Stream<Map.Entry<K,V>>
    
    Returns:
    
    the count of elements in this stream
  - anyMatch
```
public boolean anyMatch(Predicate<? super Map.Entry<K,V>> predicate)
```
    Returns whether any elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then false is returned and the predicate is not evaluated.
    This is a short-circuiting terminal operation.
    This method evaluates the existential quantification of the predicate over the elements of the stream (for some x P(x)).
    
    Specified by:
    
    anyMatch in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to elements of this stream
    
    Returns:
    
    true if any elements of the stream match the provided predicate, otherwise false
  - anyMatch
```
public boolean anyMatch(BiPredicate<? super K,? super V> predicate)
```
    Returns whether any key-value pairs of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then false is returned and the predicate is not evaluated.
    This is a short-circuiting terminal operation.
    This method evaluates the existential quantification of the predicate over the elements of the stream (for some x P(x)).
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to key-value pairs of this stream
    
    Returns:
    
    true if any key-value pairs of the stream match the provided predicate, otherwise false
  - allMatch
```
public boolean allMatch(Predicate<? super Map.Entry<K,V>> predicate)
```
    Returns whether all elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.
    This is a short-circuiting terminal operation.
    This method evaluates the universal quantification of the predicate over the elements of the stream (for all x P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always true (regardless of P(x)).
    
    Specified by:
    
    allMatch in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to elements of this stream
    
    Returns:
    
    true if either all elements of the stream match the provided predicate or the stream is empty, otherwise false
  - allMatch
```
public boolean allMatch(BiPredicate<? super K,? super V> predicate)
```
    Returns whether all key-value pairs of this stream match the provided predicate. May not evaluate the predicate on all key-value pairs if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.
    This is a short-circuiting terminal operation.
    This method evaluates the universal quantification of the predicate over the elements of the stream (for all x P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always true (regardless of P(x)).
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to key-value pairs of this stream
    
    Returns:
    
    true if either all key-value pairs of the stream match the provided predicate or the stream is empty, otherwise false
  - noneMatch
```
public boolean noneMatch(Predicate<? super Map.Entry<K,V>> predicate)
```
    Returns whether no elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.
    This is a short-circuiting terminal operation.
    This method evaluates the universal quantification of the negated predicate over the elements of the stream (for all x ~P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always true, regardless of P(x).
    
    Specified by:
    
    noneMatch in interface Stream<Map.Entry<K,V>>
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to elements of this stream
    
    Returns:
    
    true if either no elements of the stream match the provided predicate or the stream is empty, otherwise false
  - noneMatch
```
public boolean noneMatch(BiPredicate<? super K,? super V> predicate)
```
    Returns whether no key-value pairs of this stream match the provided predicate. May not evaluate the predicate on all key-value pairs if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.
    This is a short-circuiting terminal operation.
    This method evaluates the universal quantification of the negated predicate over the elements of the stream (for all x ~P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always true, regardless of P(x).
    
    Parameters:
    
    predicate - a non-interfering, stateless predicate to apply to key-value pairs of this stream
    
    Returns:
    
    true if either no key-value pairs of the stream match the provided predicate or the stream is empty, otherwise false
  - findFirst
```
public Optional<Map.Entry<K,V>> findFirst()
```
    Returns an Optional describing the first element of this stream, or an empty Optional if the stream is empty. If the stream has no encounter order, then any element may be returned.
    This is a short-circuiting terminal operation.
    
    Specified by:
    
    findFirst in interface Stream<Map.Entry<K,V>>
    
    Returns:
    
    an Optional describing the first element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the element selected is null
  - findAny
```
public Optional<Map.Entry<K,V>> findAny()
```
    Returns an Optional describing some element of the stream, or an empty Optional if the stream is empty.
    This is a short-circuiting terminal operation.
    The behavior of this operation is explicitly nondeterministic; it is free to select any element in the stream. This is to allow for maximal performance in parallel operations; the cost is that multiple invocations on the same source may not return the same result. (If a stable result is desired, use findFirst() instead.)
    
    Specified by:
    
    findAny in interface Stream<Map.Entry<K,V>>
    
    Returns:
    
    an Optional describing some element of this stream, or an empty Optional if the stream is empty
    
    Throws:
    
    NullPointerException - if the element selected is null
    
    See Also:
    
    findFirst()
  - iterator
```
public Iterator<Map.Entry<K,V>> iterator()
```
    Returns an iterator for the elements of this stream.
    This is a terminal operation.
    
    Specified by:
    
    iterator in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    Returns:
    
    the element iterator for this stream
  - spliterator
```
public Spliterator<Map.Entry<K,V>> spliterator()
```
    Returns a spliterator for the elements of this stream.
    This is a terminal operation.
    
    Specified by:
    
    spliterator in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    Returns:
    
    the element spliterator for this stream
  - isParallel
```
public boolean isParallel()
```
    Returns whether this stream, if a terminal operation were to be executed, would execute in parallel. Calling this method after invoking an terminal stream operation method may yield unpredictable results.
    
    Specified by:
    
    isParallel in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    Returns:
    
    true if this stream would execute in parallel if executed
  - sequential
```
public MapStream<K,V> sequential()
```
    Returns an equivalent stream that is sequential. May return itself, either because the stream was already sequential, or because the underlying stream state was modified to be sequential.
    This is an intermediate operation.
    
    Specified by:
    
    sequential in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    Returns:
    
    a sequential stream
  - parallel
```
public MapStream<K,V> parallel()
```
    Returns an equivalent stream that is parallel. May return itself, either because the stream was already parallel, or because the underlying stream state was modified to be parallel.
    This is an intermediate operation.
    
    Specified by:
    
    parallel in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    Returns:
    
    a parallel stream
  - unordered
```
public MapStream<K,V> unordered()
```
    Returns an equivalent stream that is unordered. May return itself, either because the stream was already unordered, or because the underlying stream state was modified to be unordered.
    This is an intermediate operation.
    
    Specified by:
    
    unordered in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    Returns:
    
    an unordered stream
  - onClose
```
public MapStream<K,V> onClose(Runnable closeHandler)
```
    Returns an equivalent stream with an additional close handler. Close handlers are run when the close() method is called on the stream, and are executed in the order they were added. All close handlers are run, even if earlier close handlers throw exceptions. If any close handler throws an exception, the first exception thrown will be relayed to the caller of close(), with any remaining exceptions added to that exception as suppressed exceptions (unless one of the remaining exceptions is the same exception as the first exception, since an exception cannot suppress itself.) May return itself.
    This is an intermediate operation.
    
    Specified by:
    
    onClose in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    Parameters:
    
    closeHandler - a task to execute when the stream is closed
    
    Returns:
    
    a stream with a handler that is run if the stream is closed
  - close
```
public void close()
```
    Closes this stream, causing all close handlers for this stream pipeline to be called.
    
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface BaseStream<Map.Entry<K,V>,Stream<Map.Entry<K,V>>>
    
    See Also:
    
    AutoCloseable.close()
  - toMap
```
public Map<K,V> toMap()
```
    Accumulates all key-value pairs of this MapStream into a Map.
    If the mapped keys contains duplicates (according to Object.equals(Object)), an IllegalStateException is thrown when the collection operation is performed. If the mapped keys may have duplicates, use toMap(BinaryOperator) instead.
    The returned Map is not concurrent. For parallel stream pipelines, the combiner function operates by merging the keys from one map into another, which can be an expensive operation. If it is not required that results are inserted into the Map in encounter order, using toConcurrentMap() may offer better parallel performance.
    
    Returns:
    
    a Map whose keys and values are identical to the entries of this stream
    
    See Also:
    
    toMap(BinaryOperator), toConcurrentMap()
  - toMap
```
public Map<K,V> toMap(BinaryOperator<V> mergeFunction)
```
    Accumulates all key-value pairs of this MapStream into a Map.
    If the mapped keys contains duplicates (according to Object.equals(Object)), the values are merged using the provided merging function.
    There are multiple ways to deal with collisions between multiple elements mapping to the same key. The other forms of toMap simply use a merge function that throws unconditionally, but you can easily write more flexible merge policies.
    The returned Map is not concurrent. For parallel stream pipelines, the combiner function operates by merging the keys from one map into another, which can be an expensive operation. If it is not required that results are merged into the Map in encounter order, using toConcurrentMap(BinaryOperator) may offer better parallel performance.
    
    Parameters:
    
    mergeFunction - a merge function, used to resolve collisions between values associated with the same key, as supplied to Map.merge(Object, Object, BiFunction)
    
    Returns:
    
    a Map whose keys and values are identical to the entries of this stream with any collisions handled
    
    See Also:
    
    toMap(), toConcurrentMap(BinaryOperator)
  - toConcurrentMap
```
public Map<K,V> toConcurrentMap()
```
    Accumulates all key-value pairs of this MapStream into a ConcurrentMap.
    If the mapped keys contains duplicates (according to Object.equals(Object)), an IllegalStateException is thrown when the collection operation is performed. If the mapped keys may have duplicates, use toConcurrentMap(BinaryOperator) instead.
    It is common for either the key or the value to be the input elements. In this case, the utility method Function.identity() may be helpful.
    This is a concurrent and unordered Collector.
    
    Returns:
    
    a ConcurrentMap whose keys are taken from this stream
    
    See Also:
    
    toMap(), toConcurrentMap(BinaryOperator)
  - toConcurrentMap
```
public Map<K,V> toConcurrentMap(BinaryOperator<V> mergeFunction)
```
    Accumulates all key-value pairs of this MapStream into a ConcurrentMap.
    If the mapped keys contains duplicates (according to Object.equals(Object)), the value mapping function is applied to each equal element, and the results are merged using the provided merging function.
    There are multiple ways to deal with collisions between multiple elements mapping to the same key. The other forms of toConcurrentMap simply use a merge function that throws unconditionally, but you can easily write more flexible merge policies.
    
    Parameters:
    
    mergeFunction - a merge function, used to resolve collisions between values associated with the same key, as supplied to Map.merge(Object, Object, BiFunction)
    
    Returns:
    
    a ConcurrentMap whose keys are taken from this stream
    
    See Also:
    
    toConcurrentMap(), toMap(BinaryOperator)
  - toSortedMap
```
public SortedMap<K,V> toSortedMap()
```
    Accumulates all key-value pairs of this MapStream into a SortedMap.
    If the mapped keys contains duplicates (according to Object.equals(Object)), an IllegalStateException is thrown when the collection operation is performed. If the mapped keys may have duplicates, use toSortedMap(BinaryOperator) instead.
    If the keys are not Comparable, a java.lang.ClassCastException may be thrown when the terminal operation is executed. It is therefore better to use toSortedMapByKey(Comparator) since it allows you to specify a comparator to use when comparing the keys.
    The returned Map is not concurrent. For parallel stream pipelines, use toConcurrentNavigableMap() instead.
    
    Returns:
    
    a Map whose keys and values are identical to the entries of this stream
    
    See Also:
    
    toMap(BinaryOperator), toConcurrentMap()
  - toSortedMapByKey
```
public SortedMap<K,V> toSortedMapByKey(Comparator<K> keyComparator)
```
    Accumulates all key-value pairs of this MapStream into a SortedMap, sorting the entries by applying the specified comparator to the keys of the stream.
    If the mapped keys contains duplicates (according to Object.equals(Object)), an IllegalStateException is thrown when the collection operation is performed. If the mapped keys may have duplicates, use toSortedMap(Comparator, BinaryOperator) instead.
    The returned Map is not concurrent. For parallel stream pipelines, use toConcurrentNavigableMap() instead.
    
    Parameters:
    
    keyComparator - the comparator to use when sorting the keys
    
    Returns:
    
    a SortedMap whose keys and values are identical to the entries of this stream
    
    See Also:
    
    toMap(BinaryOperator), toConcurrentMap(), toSortedMap()
  - toSortedMap
```
public SortedMap<K,V> toSortedMap(BinaryOperator<V> mergeFunction)
```
    Accumulates all key-value pairs of this MapStream into a SortedMap.
    If the mapped keys contains duplicates (according to Object.equals(Object)), the values are merged using the provided merging function.
    There are multiple ways to deal with collisions between multiple elements mapping to the same key. The other forms of toSortedMap simply use a merge function that throws unconditionally, but you can easily write more flexible merge policies.
    The returned SortedMap is not concurrent. For parallel stream pipelines, the combiner function operates by merging the keys from one map into another, which can be an expensive operation. If it is not required that results are merged into the Map in encounter order, using toConcurrentNavigableMap(BinaryOperator) may offer better parallel performance.
    
    Parameters:
    
    mergeFunction - a merge function, used to resolve collisions between values associated with the same key, as supplied to Map.merge(Object, Object, BiFunction)
    
    Returns:
    
    a SortedMap whose keys and values are identical to the entries of this stream with any collisions handled
    
    See Also:
    
    toMap(), toSortedMap(), toConcurrentMap(BinaryOperator)
  - toSortedMap
```
public SortedMap<K,V> toSortedMap(Comparator<K> keyComparator,
                                  BinaryOperator<V> mergeFunction)
```
    Accumulates all key-value pairs of this MapStream into a SortedMap, sorting the entries by applying the specified comparator to the keys of the stream.
    If the mapped keys contains duplicates (according to Object.equals(Object)), the values are merged using the provided merging function.
    There are multiple ways to deal with collisions between multiple elements mapping to the same key. The other forms of toSortedMap simply use a merge function that throws unconditionally, but you can easily write more flexible merge policies.
    The returned SortedMap is not concurrent. For parallel stream pipelines, the combiner function operates by merging the keys from one map into another, which can be an expensive operation. If it is not required that results are merged into the Map in encounter order, using toConcurrentNavigableMap(Comparator, BinaryOperator) may offer better parallel performance.
    
    Parameters:
    
    keyComparator - the comparator to use for determining the order of the keys
    
    mergeFunction - a merge function, used to resolve collisions between values associated with the same key, as supplied to Map.merge(Object, Object, BiFunction)
    
    Returns:
    
    a SortedMap whose keys and values are identical to the entries of this stream with any collisions handled
    
    See Also:
    
    toMap(), toSortedMap(), toConcurrentMap(BinaryOperator)
  - toConcurrentNavigableMap
```
public ConcurrentNavigableMap<K,V> toConcurrentNavigableMap()
```
    Accumulates all key-value pairs of this MapStream into a ConcurrentNavigableMap.
    If the mapped keys contains duplicates (according to Object.equals(Object)), an IllegalStateException is thrown when the collection operation is performed. If the mapped keys may have duplicates, use toConcurrentNavigableMap(BinaryOperator) instead.
    If the keys are not Comparable, a java.lang.ClassCastException may be thrown when the terminal operation is executed. It is therefore better to use toConcurrentNavigableMapByKey(Comparator) since it allows you to specify a comparator to use when comparing the keys.
    
    Returns:
    
    a ConcurrentNavigableMap whose keys and values are identical to the entries of this stream
    
    See Also:
    
    toMap(BinaryOperator), toConcurrentMap()
  - toConcurrentNavigableMapByKey
```
public ConcurrentNavigableMap<K,V> toConcurrentNavigableMapByKey(Comparator<K> keyComparator)
```
    Accumulates all key-value pairs of this MapStream into a ConcurrentNavigableMap, sorting the entries by applying the specified comparator to the keys of the stream.
    If the mapped keys contains duplicates (according to Object.equals(Object)), an IllegalStateException is thrown when the collection operation is performed. If the mapped keys may have duplicates, use toConcurrentNavigableMap(Comparator, BinaryOperator) instead.
    
    Parameters:
    
    keyComparator - the comparator to use when sorting the keys
    
    Returns:
    
    a ConcurrentNavigableMap whose keys and values are identical to the entries of this stream
    
    See Also:
    
    toMap(BinaryOperator), toConcurrentMap(), toSortedMap()
  - toConcurrentNavigableMap
```
public ConcurrentNavigableMap<K,V> toConcurrentNavigableMap(BinaryOperator<V> mergeFunction)
```
    Accumulates all key-value pairs of this MapStream into a ConcurrentNavigableMap.
    If the mapped keys contains duplicates (according to Object.equals(Object)), the values are merged using the provided merging function.
    There are multiple ways to deal with collisions between multiple elements mapping to the same key. The other forms of toConcurrentNavigableMap simply use a merge function that throws unconditionally, but you can easily write more flexible merge policies.
    
    Parameters:
    
    mergeFunction - a merge function, used to resolve collisions between values associated with the same key, as supplied to Map.merge(Object, Object, BiFunction)
    
    Returns:
    
    a ConcurrentNavigableMap whose keys and values are identical to the entries of this stream with any collisions handled
    
    See Also:
    
    toMap(), toSortedMap(), toConcurrentMap(BinaryOperator)
  - toConcurrentNavigableMap
```
public ConcurrentNavigableMap<K,V> toConcurrentNavigableMap(Comparator<K> keyComparator,
                                                            BinaryOperator<V> mergeFunction)
```
    Accumulates all key-value pairs of this MapStream into a ConcurrentNavigableMap, sorting the entries by applying the specified comparator to the keys of the stream.
    If the mapped keys contains duplicates (according to Object.equals(Object)), the values are merged using the provided merging function.
    There are multiple ways to deal with collisions between multiple elements mapping to the same key. The other forms of toConcurrentNavigableMap simply use a merge function that throws unconditionally, but you can easily write more flexible merge policies.
    
    Parameters:
    
    keyComparator - the comparator to use for determining the order of the keys
    
    mergeFunction - a merge function, used to resolve collisions between values associated with the same key, as supplied to Map.merge(Object, Object, BiFunction)
    
    Returns:
    
    a ConcurrentNavigableMap whose keys and values are identical to the entries of this stream with any collisions handled
    
    See Also:
    
    toMap(), toSortedMap(), toConcurrentMap(BinaryOperator)
  - toList
```
public List<Map.Entry<K,V>> toList()
```
    Accumulates all entries of this MapStream into a List.
    The returned List is not concurrent.
    
    Returns:
    
    a List that contains all the entities of the stream
  - comparing
```
@SafeVarargs
public static <K> Comparator<K> comparing(Function<K,? extends Comparable<?>>... methods)
```
    Utility method for creating a composed comparator that begins by comparing the first value and if it is equal, continues to the next one.
    
    Type Parameters:
    
    K - the type of the key to compare
    
    Parameters:
    
    methods - methods for comparing the key ordered by priority
    
    Returns:
    
    a composite comparator that checks the key using the supplied methods in order
  - throwingMerger
```
public static <T> BinaryOperator<T> throwingMerger()
```
    Returns a merge function, suitable for use in Map.merge() or toMap(), which always throws IllegalStateException. This can be used to enforce the assumption that the elements being collected are distinct.
    
    Type Parameters:
    
    T - the type of input arguments to the merge function
    
    Returns:
    
    a merge function which always throw IllegalStateException

Class MapStream<K,V>

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.stream.Stream

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.stream.Stream

Method Detail

of

of

of

of

fromKeys

fromValues

fromStream

empty

flip

filter

filter

filterKey

filterValue

map

map

mapKey

mapKey

mapValue

mapValue

mapToInt

mapToInt

mapToLong

mapToLong

mapToDouble

mapToDouble

flatMap

flatMap

flatMapKey

flatMapKey

flatMapValue

flatMapValue

flatMapToInt

flatMapToInt

flatMapToLong

flatMapToLong

flatMapToDouble

flatMapToDouble

keys

values

distinct

distinctKeys

distinctValues

distinctKeys

distinctValues

sorted

sorted

sortedByKey

sortedByValue

peek

peek

limit

skip

forEach

forEach

forEachOrdered

forEachOrdered

toArray

toArray

reduce

reduce

reduce

collect

collect

groupingBy

min

minByKey

minByValue

max

maxByKey

maxByValue

count

anyMatch

anyMatch