code: def delete_relation(self, src, relation, *targets):
          ''' can be both used as (src, relation, dest) for a single relation or
              (src, relation) to delete all relations of that type from the src '''
          self.__require_string__(relation)
          if len(targets):
              for i in targets:
                  self._delete_single_relation(src, relation, i)
          else:
              # delete all connections of that relation from src
              for i in list(self.find(src, relation)):
                  self._delete_single_relation(src, relation, if delete_relation(self, src, relation, *targets):
          ''' can be both used as (src, relation, dest) for a single relation or
              (src, relation) to delete all relations of that type from the src '''
          self.__require_string__(relation)
          if len(targets):
              for i in targets:
                  self._delete_single_relation(src, relation, i)
          else:
              # delete all connections of that relation from src
              for i in list(self.find(src, relation)):
                  self._delete_single_relation(src, relation, i)
docs: can be both used as (src, relation, dest) for a single relation or
              (src, relation) to delete all relations of that type from the src