Subclasses of Source MUST override this method.
Subclasses of Source MUST override this method. They may call out to TestTapFactory for making Taps suitable for testing.
Because TupleConverter cannot be covariant, we need to jump through this hoop.
Because TupleConverter cannot be covariant, we need to jump through this hoop. A typical implementation might be: (implicit conv: TupleConverter[T]) and then:
override def converter[U >: T] = TupleConverter.asSuperConverter[T, U](conv)
If you want to filter, you should use this and output a 0 or 1 length Iterable.
If you want to filter, you should use this and output a 0 or 1 length Iterable. Filter does not change column names, and we generally expect to change columns here
Allows you to read a Tap on the submit node NOT FOR USE IN THE MAPPERS OR REDUCERS.
Allows you to read a Tap on the submit node NOT FOR USE IN THE MAPPERS OR REDUCERS. Typical use might be to read in Job.next to determine if another job is needed
write the pipe and return the input so it can be chained into the next operation
write the pipe and return the input so it can be chained into the next operation