def has_node(self, n):
        """Return True if the graph contains the node n.

        Parameters
        ----------
        n : node

        Examples
        --------
        >>> G = nx.Graph()   # or DiGraph, MultiGraph, MultiDiGraph, etc
        >>> G.add_path([0,1,2])
        >>> G.has_node(0)
        True

        It is more readable and simpler to use

        >>> 0 in G
        True

        """
        try:
            return n in self.node
        except __HOLE__:
            return False
dataset/ETHPy150Open gkno/gkno_launcher/src/networkx/classes/graph.py/Graph.has_node