<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def clean(self):
 """ Get rid of stale connections. """

        # Note that we do not close the connection here -- somebody
        # may still be reading from it.
        while len(self.queue) > 0 and self._pair_stale(self.queue[0]):
            self.queue.pop(0)