code: def test_xs_droplevel_false_view(
      self, using_copy_on_write, warn_copy_on_write
  ):
      # GH#37832
      df = DataFrame([[1, 2, 3]], columns=Index(["a", "b", "c"]))
      result = df.xs("a", axis=1, drop_level=False)
      # check that result still views the same data as df
      assert np.shares_memory(
          result.iloc[:, 0]._values, df.iloc[:, 0]._values
      )
  
      with tm.assert_cow_warning(warn_copy_on_write):
          df.iloc[0, 0] = 2
      if using_copy_on_write:
          # with copy on write the subset is never modified
          expected = DataFrame({"a": [1]})
      else:
          # modifying original df also modifies result when having a single block
          expected = DataFrame({"a": [2]})
      tm.assert_frame_equal(result, expected)
  
      # with mixed dataframe, modifying the parent doesn't modify result
      # TODO the "split" path behaves differently here as with single block
      df = DataFrame([[1, 2.5, "a"]], columns=Index(["a", "b", "c"]))
      result = df.xs("a", axis=1, drop_level=False)
      df.iloc[0, 0] = 2
      if using_copy_on_write:
          # with copy on write the subset is never modified
          expected = DataFrame({"a": [1]})
      else:
          # FIXME: iloc does not update the array inplace using
          # "split" path
          expected = DataFrame({"a": [1]})
      tm.assert_frame_equal(result, expected)
  
imports: import re
  import numpy
  import pytest
  from pandas.errors import SettingWithCopyError
  from pandas import DataFrame, Index, IndexSlice, MultiIndex, Series, concat
  import pandas._testing
  from pandas.tseries.offsets import BDay
label_desc: Use image node_id 18 for calling the TestXSWithMultiIndex obj's underlying member method code with example usage: obj.test_xs_droplevel_false_view(using_copy_on_write, warn_copy_on_write) without return types