code: def test_setting_with_copy_bug(
      self, using_copy_on_write, warn_copy_on_write
  ):
      # operating on a copy
      df = DataFrame(
          {
              "a": list(range(4)),
              "b": list("ab.."),
              "c": ["a", "b", np.nan, "d"],
          }
      )
      df_original = df.copy()
      mask = pd.isna(df.c)
  
      if using_copy_on_write:
          with tm.raises_chained_assignment_error():
              df[["c"]][mask] = df[["b"]][mask]
          tm.assert_frame_equal(df, df_original)
      elif warn_copy_on_write:
          with tm.raises_chained_assignment_error():
              df[["c"]][mask] = df[["b"]][mask]
      else:
          with pytest.raises(SettingWithCopyError, match=msg):
              df[["c"]][mask] = df[["b"]][mask]
  
imports: from string import ascii_letters
  import numpy
  import pytest
  from pandas.errors import SettingWithCopyError, SettingWithCopyWarning
  import pandas
  from pandas import DataFrame, Index, Series, Timestamp, date_range, option_context
  import pandas._testing
label_desc: Use image node_id 17 for calling the TestChaining obj's underlying member method code with example usage: obj.test_setting_with_copy_bug(using_copy_on_write, warn_copy_on_write) without return types