code: def list_relations(self):
          ''' list every relation in the database as (src, relation, dst) '''
          for node in self.iter_nodes():
              for relation, target in self.relations_of(node.obj, True):
                  yield node.obj, relation, targef list_relations(self):
          ''' list every relation in the database as (src, relation, dst) '''
          for node in self.iter_nodes():
              for relation, target in self.relations_of(node.obj, True):
                  yield node.obj, relation, target
docs: list every relation in the database as (src, relation, dst)