code: def test_varselect():
      vars = ["text"]
      df = pd.DataFrame({"text": ["a", "b", "c"], "numbers": [1, 2, 3]})
      selector = preprocessing.SelectField(
          cols=vars, single_dimension=True
      )
      X_t = selector.fit_transform(df)
      assert X_t.shape == (3,)
  
file_path: sk-dist/skdist/tests/test_preprocessing.py
label_desc: Use image node_id 2 for calling a global function with example usage: test_varselect() without return types