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 function.
See the {@link CompletionStage} documentation for rules
covering exceptional completion.
@param other the other CompletionStage
@param fn the function to use to compute the value of the
returned CompletionStage
@param executor the executor to use for asynchronous execution
@param (U) the function's return type
@return the new CompletionStage
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 function.
See the {@link CompletionStage} documentation for rules covering exceptional completion.
@param other the other CompletionStage @param fn the function to use to compute the value of the returned CompletionStage @param executor the executor to use for asynchronous execution @param (U) the function's return type @return the new CompletionStage