thenAcceptBothAsync
abstract override fun <U> thenAcceptBothAsync(other: CompletionStage<out U>, action: BiConsumer<in T, in U>): DelayableCompletableFuture<Void?>
abstract override fun <U> thenAcceptBothAsync(other: CompletionStage<out U>, action: BiConsumer<in T, in U>, executor: Executor): DelayableCompletableFuture<Void?>