code: def test_fit(model, df_clean):
      tf, vectors_tokenized = model.tokenize_text(df_clean)
      model.fit(tf, vectors_tokenized)
      assert type(model.tfidf_matrix) == scipy.sparse.csr.csr_matrix
  
file_path: recommenders/tests/unit/recommenders/models/test_tfidf_utils.py
imports: import pytest
  import scipy
  import pandas
  from recommenders.models.tfidf.tfidf_utils import TfidfRecommender
label_desc: Use image node_id 8 for calling a global function with example usage: test_fit(model, df_clean) without return types