code: def test_drop_duplicate_columns(df_duplicated_columns):
      # df_duplicated_columns contains columns 'a', duplicated three times
      clean_df = df_duplicated_columns.drop_duplicate_columns(
          column_name="a"
      )
      assert clean_df.columns.to_list() == ["b", "a", "a"]
      expected_df = pd.DataFrame(
          {"b": range(10), "a": range(10, 20), "a*": range(20, 30)}
      ).clean_names(remove_special=True)
      assert_frame_equal(clean_df, expected_df)
  
file_path: pyjanitor/tests/functions/test_drop_duplicate_columns.py
imports: import pandas
  import pytest
  from pandas.testing import assert_frame_equal
  import janitor
label_desc: Use image node_id 1 for calling a global function with example usage: test_drop_duplicate_columns(df_duplicated_columns) without return types