code: def test_successor(self):
      print()
      nodes = [4, 5, 8]
      e_type = "p2a"
      succes = self.graph.successor(
          edge_type=e_type,
          nodes=nodes,
      )
  
      self.assertIsInstance(succes, np.ndarray)
      ground = [[10, 11, 12, 14, 13], [], [14]]
      for succ, g in zip(succes, ground):
          self.assertIsInstance(succ, np.ndarray)
          self.assertCountEqual(succ, g)
  
      nodes = [4]
      e_type = "p2a"
      succes = self.graph.successor(
          edge_type=e_type,
          nodes=nodes,
      )
  
      self.assertIsInstance(succes, np.ndarray)
      ground = [[10, 11, 12, 14, 13]]
      for succ, g in zip(succes, ground):
          self.assertIsInstance(succ, np.ndarray)
          self.assertCountEqual(succ, g)
  
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 5 for calling the MmapHeterGraphTest obj's underlying member method code with example usage: obj.test_successor() without return types