<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def peer_address(self):
 """ Peer endpoint address as a tuple """

        if not self._peer_address:
            self._peer_address = self.proto.reader._transport.get_extra_info('peername')
            if len(self._peer_address) == 4:
                self._peer_address = self._peer_address[:2]
        return self._peer_address