code: def test_column_selector_categorical(data):
      """Tests if column selector works on categorical"""
      cols = ["dow_categorical"]
      selector = DtypeColumnSelector(include="category")
      assert selector.include == "category"
      assert selector.exclude is None
  
      result = selector.fit_transform(data)
      assert result.equals(data[cols])
  
file_path: greykite/greykite/tests/sklearn/transform/test_dtype_column_selector.py
imports: import pytest
  from greykite.common.constants import TIME_COL
  from greykite.common.testing_utils import generate_df_with_reg_for_tests
  from greykite.sklearn.transform.dtype_column_selector import DtypeColumnSelector
label_desc: Use image node_id 6 for calling a global function with example usage: test_column_selector_categorical(data) without return types