def __getitem__(self, i):
        r"""Gets the idx-th sample.

        Parameters
        -----------
        idx : int
            The sample index.

        Returns
        -------
        (dgl.DGLGraph, scipy.sparse.coo_matrix, int)
            The graph, scipy sparse coo_matrix and its label.
        """
        if self._transform is None:
            g = self.graphs[i]
        else:
            g = self._transform(self.graphs[i])
        return (g, self.pmpds[i], self.labels[i])
Gets the idx-th sample.

        Parameters
        -----------
        idx : int
            The sample index.

        Returns
        -------
        (dgl.DGLGraph, scipy.sparse.coo_matrix, int)
            The graph, scipy sparse coo_matrix and its label.
        
python/dgl/data/citation_graph.py