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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def on_peer_down(self, peer):
 """Peer down handler. Cleans up the paths in global tables that was received from this peer. """

        LOG.debug('Cleaning obsolete paths whose source/version: %s/%s',
                  peer.ip_address, peer.version_num)
        # Launch clean-up for each global tables.
        self._table_manager.clean_stale_routes(peer)