src/main/java/io/reactivex/parallel/ParallelFlowable.java
@CheckReturnValue
    @NonNull
    public final ParallelFlowable<T> doAfterNext(@NonNull Consumer<? super T> onAfterNext) {
        ObjectHelper.requireNonNull(onAfterNext, "onAfterNext is null");
        return RxJavaPlugins.onAssembly(new ParallelPeek<T>(this,
                Functions.emptyConsumer(),
                onAfterNext,
                Functions.emptyConsumer(),
                Functions.EMPTY_ACTION,
                Functions.EMPTY_ACTION,
                Functions.emptyConsumer(),
                Functions.EMPTY_LONG_CONSUMER,
                Functions.EMPTY_ACTION
                ));
    }
@CheckReturnValue
    @NonNull
    public final ParallelFlowable<T> doAfterNext(@NonNull Consumer<? super T> onAfterNext) {
        ObjectHelper.requireNonNull(onAfterNext, "onAfterNext is null");
        return RxJavaPlugins.onAssembly(new ParallelPeek<T>(this,
                Functions.emptyConsumer(),
                onAfterNext,
                Functions.emptyConsumer(),
                Functions.EMPTY_ACTION,
                Functions.EMPTY_ACTION,
                Functions.emptyConsumer(),
                Functions.EMPTY_LONG_CONSUMER,
                Functions.EMPTY_ACTION
                ));
    }
@ CheckReturnValue @ NonNull public final ParallelFlowable < T > doAfterNext ( @ NonNull Consumer < ? super T > onAfterNext ) { ObjectHelper . requireNonNull ( onAfterNext , "onAfterNext is null" ) ; return RxJavaPlugins . onAssembly ( new ParallelPeek < T > ( this , Functions . emptyConsumer ( ) , onAfterNext , Functions . emptyConsumer ( ) , Functions . EMPTY_ACTION , Functions . EMPTY_ACTION , Functions . emptyConsumer ( ) , Functions . EMPTY_LONG_CONSUMER , Functions . EMPTY_ACTION ) ) ; }
Call the specified consumer with the current element passing through any 'rail'
after it has been delivered to downstream within the rail.

@param onAfterNext the callback
@return the new ParallelFlowable instance
Call the specified consumer with the current element passing through any rail after it has been delivered to downstream within the rail .