code: def test_extract(
      self,
      setup,
      kg,
      root,
      max_depth,
      max_walks,
      with_reverse,
      wl_iterations,
  ):
      root = f"{URL}#{root}"
      walker = WLWalker(
          max_depth,
          max_walks,
          with_reverse=with_reverse,
          random_state=42,
          wl_iterations=wl_iterations,
      )
      walker._weisfeiler_lehman(kg)
      walks = walker._extract(kg, Vertex(root))[root]
      if max_walks is not None:
          if not with_reverse:
              assert len(walks) <= (max_walks * wl_iterations) + max(
                  max_depth, max_walks
              )
      for walk in walks:
          if not with_reverse:
              assert walk[0] == root
  
imports: import itertools
  import pytest
  from pyrdf2vec.graphs import KG, Vertex
  from pyrdf2vec.walkers import WLWalker
label_desc: Use image node_id 2 for calling the TestWLWalker obj's underlying member method code with example usage: obj.test_extract(setup, kg, root, max_depth, max_walks, with_reverse, wl_iterations) without return types