code: def test_node_batch_iter(self):
      print()
      batch_size = 2
      ground = [[4, 5], [6, 7], [8, 9]]
      for idx, nodes in enumerate(
          self.graph.node_batch_iter(
              batch_size=batch_size, shuffle=False, n_type="p"
          )
      ):
          self.assertEqual(len(nodes), batch_size)
          self.assertListEqual(list(nodes), ground[idx])
  
file_path: PGL/legacy/pgl/tests/test_MmapHeterGraph.py
imports: import time
  import unittest
  import json
  import os
  import numpy
  from pgl.sample import metapath_randomwalk
  from pgl.graph import Graph
  from pgl import heter_graph
  from pgl.heter_graph import MemmapHeterGraph
label_desc: Use image node_id 3 for calling the MmapHeterGraphTest obj's underlying member method code with example usage: obj.test_node_batch_iter() without return types