@Override
  public ResultStream<T> createMapSelf(ResultStream<? super T> result)
  {
    return new ResultStreamServicePrefetch<>(result, _prefetch);
  }
@ Override public ResultStream < T > createMapSelf ( ResultStream < ? super T > result ) { return new ResultStreamServicePrefetch < > ( result , _prefetch ) ; }
/*
@Override
public int getCredit()
{
return _prefetch;
}