docs: def _create_node(self, index: int, name: str, external_id: Optional[str] = None) -> IGraphNode:
          """
          Returns a new `IGraphNode` instance with the given index and name.
  
          Arguments:
              index (int): The index of the node to create.
              name (str): The name of the node to create.
              external_id (Optional[str]): The external ID of the node.
          """
          return IGraphNode(graph=self._graph, index=index, name=name, external_id=external_id)