code: def test_multiindex_diff_key_types(df_multi):
      """Test output if the keys in the dictionary are not the same type."""
      msg = "The levels in the dictionary "
      msg = "should be either all strings or all integers."
      with pytest.raises(TypeError, match=msg):
          df_multi.change_index_dtype(
              dtype={1: int, "first": "category"}
          )
  
file_path: pyjanitor/tests/functions/test_change_index_dtype.py
imports: import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
label_desc: Use image node_id 6 for calling a global function with example usage: test_multiindex_diff_key_types(df_multi) without return types