code: def test_get_walks(self, setup, kg):
      transformer = RDF2VecTransformer(verbose=2)
      assert len(transformer._walks) == 0
      with pytest.raises(ValueError):
          transformer.get_walks(kg, ["does", "not", "exist"])
      transformer.get_walks(
          kg, [f"{URL}#{entity}" for entity in ROOTS_WITHOUT_URL]
      )
      assert len(transformer._walks) > 0
  
file_path: pyRDF2Vec/tests/test_rdf2vec.py
imports: import os
  import pickle
  import numpy
  import pytest
  from pyrdf2vec.graphs import KG, Vertex
  from pyrdf2vec.rdf2vec import RDF2VecTransformer
  from pyrdf2vec.walkers import RandomWalker, WLWalker
label_desc: Use image node_id 3 for calling the TestRDF2VecTransformer obj's underlying member method code with example usage: obj.test_get_walks(setup, kg) without return types