code: def sampling_func(g, seed_nodes, labels, train_loader):
      category = "paper"
      for input_nodes, seeds, blocks in train_loader:
          seeds = seeds[category]
          feat = blocks[0].srcdata["feat"]["paper"]
      return None
  
imports: import dgl
  import torch
  import torch.nn.functional
  import time
  import argparse
  from cugraph_dgl import c
label_desc: Use image node_id 2 for calling a global function with example usage: sampling_func(g, seed_nodes, labels, train_loader) and returns: None