code: def test_rename_objects(self, float_string_frame):
      renamed = float_string_frame.rename(columns=str.upper)
  
      assert "FOO" in renamed
      assert "foo" not in renamed
  
imports: from collections import ChainMap
  import inspect
  import numpy
  import pytest
  from pandas import DataFrame, Index, MultiIndex, merge
  import pandas._testing
label_desc: Use image node_id 12 for calling the TestRename obj's underlying member method code with example usage: obj.test_rename_objects(float_string_frame) without return types