code: def get_gateway_id(self):
          
          host, _ = self.server_address
          try:
              ip_address = ipaddress.ip_address(host)
          except ValueError:
              # Only hosts using ip address supports unique id.
              return None
          if ip_address.version == 6:
              mac = get_mac_address(ip6=host)
          else:
              mac = get_mac_address(ip=host)
          return mac
docs: Return a unique id for the gateway.