code: def test_fit_transform(
      self, setup, kg, walker, sampler, is_inverse, is_split
  ):
      if "UniformSampler" in str(sampler):
          sampler = sampler()
      else:
          sampler = sampler(is_inverse, is_split)
  
      assert RDF2VecTransformer(
          walkers=[walker(2, 5, sampler, random_state=42)]
      ).fit_transform(
          kg, [f"{URL}#{entity}" for entity in ROOTS_WITHOUT_URL]
      )
  
file_path: pyRDF2Vec/tests/test_walkers_samplers.py
imports: import itertools
  import pytest
  from pyrdf2vec.graphs import KG, Vertex
  from pyrdf2vec.rdf2vec import RDF2VecTransformer
  from pyrdf2vec.walkers import AnonymousWalker, HALKWalker, NGramWalker, RandomWalker, WalkletWalker, WLWalker
  from pyrdf2vec.samplers import ObjFreqSampler, ObjPredFreqSampler, PageRankSampler, PredFreqSampler, UniformSampler, WideSampler
label_desc: Use image node_id 2 for calling the TestWalkerSampler obj's underlying member method code with example usage: obj.test_fit_transform(setup, kg, walker, sampler, is_inverse, is_split) without return types