code: def test_rename_mi(self, frame_or_series):
      obj = frame_or_series(
          [11, 21, 31],
          index=MultiIndex.from_tuples(
              [("A", x) for x in ["a", "B", "c"]]
          ),
      )
      obj.rename(str.lower)
  
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 2 for calling the TestRename obj's underlying member method code with example usage: obj.test_rename_mi(frame_or_series) without return types