Returns a new CompletionStage that, when this stage completes
normally, is executed using this stage's default asynchronous
execution facility, with this stage's result as the argument to
the supplied action.
See the {@link CompletionStage} documentation for rules
covering exceptional completion.
@param action the action to perform before completing the
returned CompletionStage
@return the new CompletionStage
Returns a new CompletionStage that, when this stage completes normally, is executed using this stage's default asynchronous execution facility, with this stage's result as the argument to the supplied action.
See the {@link CompletionStage} documentation for rules covering exceptional completion.
@param action the action to perform before completing the returned CompletionStage @return the new CompletionStage