def transform_symmetric_etype(self, c_etype, g, data_dict):
        r"""Transform the graph corresponding to a symmetric canonical edge type.

        Parameters
        ----------
        c_etype : tuple of str
            A canonical edge type.
        g : DGLGraph
            The graph.
        data_dict : dict
            The edge data to update.
        """
        if self.sym_new_etype:
            self.transform_asymmetric_etype(c_etype, g, data_dict)
        else:
            src, dst = g.edges(etype=c_etype)
            src, dst = F.cat([src, dst], dim=0), F.cat([dst, src], dim=0)
            data_dict[c_etype] = (src, dst)
Transform the graph corresponding to a symmetric canonical edge type.

        Parameters
        ----------
        c_etype : tuple of str
            A canonical edge type.
        g : DGLGraph
            The graph.
        data_dict : dict
            The edge data to update.
        
python/dgl/transforms/module.py