code: def unregister_peer(self, connection_id):
          
          public_key = self.peer_to_public_key(connection_id)
          if public_key:
              self._consensus_notifier.notify_peer_disconnected(public_key)
  
          with self._lock:
              if connection_id in self._peers:
                  del self._peers[connection_id]
                  LOGGER.debug("Removed connection_id %s, "
                               "connected identities are now %s",
                               connection_id, self._peers)
                  self._topology.set_connection_status(connection_id,
                                                       PeerStatus.TEMP)
              else:
                  LOGGER.warning("Connection unregister failed as connection "
                                 "was not registered: %s",
                                 connection_id)
docs: Removes a connection_id from the registry.
  
          Args:
              connection_id (str): A unique identifier which identifies an
                  connection on the network server socket.