docs: def setup(self, workers=1, qsize=0):
          """Setup the pool parameters like number of workers and output queue size"""
          if workers <= 0:
              raise ValueError("workers have to be greater then zero")
          if qsize < 0:
              raise ValueError("qsize have to be greater or equal zero")
          self.qsize = qsize # output que size
          self.workers = workers
          return self