docs: def list_tubes(self):
          """Return a list of tubes that this beanstalk instance knows about
  
          :rtype: list of tubes
          """
          with self._sock_ctx() as sock:
              self._send_message('list-tubes', sock)
              body = self._receive_data_with_prefix(b'OK', sock)
              tubes = yaml_load(body)
              return tubes