code: def forward(self, pos_graph, neg_graph, blocks):
      h_item = self.get_repr(blocks)
      pos_score = self.scorer(pos_graph, h_item)
      neg_score = self.scorer(neg_graph, h_item)
      return (neg_score - pos_score + 1).clamp(min=0)
  
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 2 for calling the PinSAGEModel obj's underlying member method code with example usage: obj.forward(pos_graph, neg_graph, blocks) and returns: unknown