code: def test_sort_values_stable_descending_sort(self):
      # GH#6399
      df = DataFrame(
          [[2, "first"], [2, "second"], [1, "a"], [1, "b"]],
          columns=["sort_col", "order"],
      )
      sorted_df = df.sort_values(
          by="sort_col", kind="mergesort", ascending=False
      )
      tm.assert_frame_equal(df, sorted_df)
  
imports: import numpy
  import pytest
  import pandas
  from pandas import Categorical, DataFrame, NaT, Timestamp, date_range
  import pandas._testing
  from pandas.util.version import Version
label_desc: Use image node_id 8 for calling the TestDataFrameSortValues obj's underlying member method code with example usage: obj.test_sort_values_stable_descending_sort() without return types