docs: def _load_neighbors(self) -> None:
          """
          Loads all neighbors of the node from the local database and
          from the external data source if needed.
          """
          if not self.are_neighbors_cached:
              self._load_neighbors_from_external_source()
              db: GraphDatabaseInterface = self._graph.database
              db_node: DBNode = db.Node.find_by_name(self.name)
              db_node.are_neighbors_cached = True
              db.session.commit()
              self.are_neighbors_cached = True
          if not self._are_neighbors_loaded:
              self._load_neighbors_from_database()