code: def send_task(self, task, force=True):
          '''
          dispatch task to fetcher
  
          out queue may have size limit to prevent block, a send_buffer is used
          '''
          try:
              self.out_queue.put_nowait(task)
          except Queue.Full:
              if force:
                  self._send_buffer.appendleft(task)
              else:
                  raisf send_task(self, task, force=True):
          '''
          dispatch task to fetcher
  
          out queue may have size limit to prevent block, a send_buffer is used
          '''
          try:
              self.out_queue.put_nowait(task)
          except Queue.Full:
              if force:
                  self._send_buffer.appendleft(task)
              else:
                  raise
docs: dispatch task to fetcher
  
          out queue may have size limit to prevent block, a send_buffer is used