def to_canonical_etype(self, etype):
        """Convert an edge type to the corresponding canonical edge type.

        Parameters
        ----------
        etype : str or (str, str, str)
            The edge type

        Returns
        -------
        (str, str, str)
            The corresponding canonical edge type
        """
Convert an edge type to the corresponding canonical edge type.

        Parameters
        ----------
        etype : str or (str, str, str)
            The edge type

        Returns
        -------
        (str, str, str)
            The corresponding canonical edge type
        
python/dgl/distributed/graph_partition_book.py