code: def test_setitem_change_dtype(self, multiindex_dataframe_random_data):
      frame = multiindex_dataframe_random_data
      dft = frame.T
      s = dft["foo", "two"]
      dft["foo", "two"] = s > s.median()
      tm.assert_series_equal(dft["foo", "two"], s > s.median())
      # assert isinstance(dft._data.blocks[1].items, MultiIndex)
  
      reindexed = dft.reindex(columns=[("foo", "two")])
      tm.assert_series_equal(reindexed["foo", "two"], s > s.median())
  
imports: import numpy
  import pytest
  from pandas.errors import SettingWithCopyError
  import pandas
  from pandas import DataFrame, MultiIndex, Series, date_range, isna, notna
  import pandas._testing
label_desc: Use image node_id 17 for calling the TestMultiIndexSetItem obj's underlying member method code with example usage: obj.test_setitem_change_dtype(multiindex_dataframe_random_data) without return types