code: def testRandomWalkDirectedIn(self):
      g = Graph.Tree(121, 3, mode="out")
      mode = "in"
      for _i in range(100):
          start = random.randint(40, g.vcount() - 1)
          length = random.randint(0, 4)
          walk = g.random_walk(start, length, mode)
          self.validate_walk(g, walk, start, length, mode)
  
file_path: python-igraph/tests/test_walks.py
imports: import random
  import unittest
  from igraph import Graph, InternalError
label_desc: Use image node_id 6 for calling the RandomWalkTests obj's underlying member method code with example usage: obj.testRandomWalkDirectedIn() without return types