def map_to_per_etype(self, ids):
        """Map homogeneous edge IDs to type-wise IDs and edge types.

        Parameters
        ----------
        ids : tensor
            Homogeneous edge IDs.

        Returns
        -------
        (tensor, tensor)
            edge type IDs and type-wise edge IDs.
        """
Map homogeneous edge IDs to type-wise IDs and edge types.

        Parameters
        ----------
        ids : tensor
            Homogeneous edge IDs.

        Returns
        -------
        (tensor, tensor)
            edge type IDs and type-wise edge IDs.
        
python/dgl/distributed/graph_partition_book.py