close connection to data source invoked in onStop() method of Task
close connection to data source invoked in onStop() method of Task
open connection to data source invoked in onStart() method of Task
open connection to data source invoked in onStart() method of Task
is the task context at runtime
is the start time of system
read a number of messages from data source.
read a number of messages from data source. invoked in each onNext() method of Task
max number of messages to read
a list of messages wrapped in Message