OnSubscribe<T> functions that respond correctly to back pressure requests from subscribers.
BlockingObservable is a variety of
Observable that provides blocking operators.
ConnectableObservable resembles an ordinary
Observable, except that it does not begin emitting items when it is subscribed to, but only when its
ConnectableObservable.connect() method is called.
Observable that has been grouped by key, the value of which can be obtained with
GroupedObservable.getKey() .
OnSubscribe<T> functions that respond correctly to back pressure requests from subscribers.