def __read_graph(self, network_filename):
        """
        Read .ncol network file

        :param network_filename: complete path for the .ncol file
        :return: an undirected network
        """
        self.g = nx.read_edgelist(network_filename, nodetype=int)
Read .ncol network file

        :param network_filename: complete path for the .ncol file
        :return: an undirected network