public final Disposable subscribe(@Nullable Consumer<? super T> onNext, Consumer<? super Throwable>
			onError){
		return subscribe(onNext, onError, null);
	}
public final Disposable subscribe(@Nullable Consumer<? super T> onNext, Consumer<? super Throwable>
			onError){
		return subscribe(onNext, onError, null);
	}
public final Disposable subscribe ( @ Nullable Consumer < ? super T > onNext , Consumer < ? super Throwable > onError ) { return subscribe ( onNext , onError , null ) ; }
Subscribes to this {@link ParallelFlux} by providing an onNext and onError callback
and triggers the execution chain for all 'rails'.

@param onNext consumer of onNext signals
@param onError consumer of error signal
Subscribes to this { @link ParallelFlux } by providing an onNext and onError callback and triggers the execution chain for all rails .