Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed using the supplied executor, with the corresponding result as argument to the supplied action. See the CompletionStage documentation for rules covering exceptional completion.

Parameters:

other		the other CompletionStage
action		the action to perform before completing the returned CompletionStage
executor		the executor to use for asynchronous execution

Returns:  the new CompletionStage