code: def get(self, interface_id):
          
          for interface in self:
              if interface.nicid == str(interface_id) or \
                  interface.dynamic_nicid == str(interface_id):
                  return interface
          raise InterfaceNotFound('Specified interface {} does not exist on '
              'this engine.'.format(interface_id))
docs: Obtain routing configuration for a specific interface by
          ID.
  
          .. note::
              If interface is a VLAN, you must use a str to specify the
              interface id, such as '3.13' (interface 3, VLAN 13)
  
          :param str,int interface_id: interface identifier
          :raises InterfaceNotFound: invalid interface for engine
          :return: Routing element, or None if not found
          :rtype: Routing