Adds the node with the given name to the graph.

        Arguments:
            node_name (str): The name of the node to add to the graph.
            external_id (Optional[str]): The external ID of the node.

def add_node(self, node_name: str, external_id: Optional[str] = None) -> None:
        """
        Adds the node with the given name to the graph.

        Arguments:
            node_name (str): The name of the node to add to the graph.
            external_id (Optional[str]): The external ID of the node.
        """
        self._nodes.add_node_by_name(node_name, external_id)