docstr: item_item_graph : graph consists of edges connecting the pairs
  h : hidden state of every node
code: 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
  
imports: import argparse
  import pickle
  import time
  import dgl
  import dgl.function
  import numpy
  import torch
  import torch.nn
  import torch.nn.functional
  from torch.utils.data import DataLoader, IterableDataset
  from ..None import utils
label_desc: Use image node_id 3 for calling the ItemToItemScorer obj's underlying member method code with example usage: obj.forward(item_item_graph, h) and returns: pair_score