code: def test_original_data_type(dataframe):
      df = pd.DataFrame(range(3), columns=["col1"])
      df_original = df.copy()
  
      df.change_type("col1", dtype=str)
  
      # 'cols' is still int type not str type
      assert_frame_equal(df, df_original)
  
file_path: pyjanitor/tests/functions/test_change_type.py
imports: import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
label_desc: Use image node_id 7 for calling a global function with example usage: test_original_data_type(dataframe) without return types