code: def add(self, element):
          
          if self.level == 'interface':
              for network in self:
                  if from_meta(network) == element:
                      return False
          
              self.data['antispoofing_node'].append({
                  'antispoofing_node': [],
                  'auto_generated': 'false',
                  'href': element.href,
                  'level': self.level,
                  'validity': 'enable',
                  'name': element.name})
  
              self.update()
              return True
          return False
docs: Add an entry to this antispoofing node level.
          Entry can be either href or network elements specified
          in :py:class:`smc.elements.network`
          ::
  
              if0 = engine.antispoofing.get(0)
              if0.add(Network('foonet'))
  
          :param Element element: entry to add, i.e. Network('mynetwork'), Host(..)
          :raises CreateElementFailed: failed adding entry
          :raises ElementNotFound: element entry specified not in SMC
          :return: whether entry was added
          :rtype: bool