code: def add_next_hop(self, access_or_prefix_list, rank=None):
          
          self.conditions.append(dict(
              next_hop_ref=access_or_prefix_list.href,
              type='next_hop',
              rank=rank))
docs: Add a next hop condition. Next hop elements must be
          of type IPAccessList or IPPrefixList.
          
          :raises ElementNotFound: If element specified does not exist