code: def message(self, x_j):
      return x_j
  
imports: import argparse
  import os.path
  import time
  import torch
  import torch.nn.functional
  from tqdm import tqdm
  from torch_geometric.datasets import Reddit, Reddit2
  from torch_geometric.nn.conv import MessagePassing
  from torch.nn import Linear
  from torch import Tensor
  from logger import Logger
  from torch_geometric.data import NeighborSampler
label_desc: Use image node_id 3 for calling the Conv obj's underlying member method code with example usage: obj.message(x_j) and returns: x_j