public static <T>ParallelFlowable<T> from(Publisher<? extends T> source,int parallelism){
  return from(source,parallelism,Flowable.bufferSize());
}

public static < T > ParallelFlowable < T > from ( Publisher < ? extends T > source , int parallelism ) { return from ( source , parallelism , Flowable . bufferSize ( ) ) ; }
take a publisher and prepare to consume it on parallallism number of ' rails ' in a round - robin fashion .
