def forward(self, item_item_graph, h):
        """
        item_item_graph : graph consists of edges connecting the pairs
        h : hidden state of every node
        """
        with item_item_graph.local_scope():
            item_item_graph.ndata["h"] = h
            item_item_graph.apply_edges(fn.u_dot_v("h", "h", "s"))
            item_item_graph.apply_edges(self._add_bias)
            pair_score = item_item_graph.edata["s"]
        return pair_score

        item_item_graph : graph consists of edges connecting the pairs
        h : hidden state of every node
        
examples/pytorch/pinsage/layers.py