code: def infer_node_generator(self):
      ntype_list = self.graph.get_node_types()
      node_generators = {}
      for ntype in ntype_list:
          for batch_nodes in self.graph.node_batch_iter(
              batch_size=self.batch_node_size,
              shuffle=False,
              node_type=ntype,
              rank=self.rank,
              nrank=self.nrank,
          ):
              yield (batch_nodes, 0)
  
file_path: PGL/apps/Graph4Rec/env_run/src/datasets/node.py
imports: import os
  import sys
  import time
  import warnings
  import numpy
  from collections import defaultdict
  from pgl.utils.logger import log
  from pgl.distributed import DistGraphClient, DistGraphServer
  from utils.config import prepare_config
label_desc: Use image node_id 3 for calling the NodeGenerator obj's underlying member method code with example usage: obj.infer_node_generator() without return types