code: protected final boolean validate(Subscriber<?>[] subscribers) {
  		int p = parallelism();
  		if (subscribers.length != p) {
  			IllegalArgumentException iae = new IllegalArgumentException("parallelism = " +
  					"" + p + ", subscribers = " + subscribers.length);
  			for (Subscriber<?> s : subscribers) {
  				Operators.error(s, iae);
  			}
  			return false;
  		}
  		return true;
  	}
docs: Validates the number of subscribers and returns true if their number matches the
  parallelism level of this ParallelFlux.
  
  @param subscribers the array of Subscribers
  
  @return true if the number of subscribers equals to the parallelism level