code: def test_sort_index_multilevel_repr_8017(self, gen, extra):
      data = np.random.default_rng(2).standard_normal((3, 4))
  
      columns = MultiIndex.from_tuples([("red", i) for i in gen])
      df = DataFrame(data, index=list("def"), columns=columns)
      df2 = pd.concat(
          [
              df,
              DataFrame(
                  "world",
                  index=list("def"),
                  columns=MultiIndex.from_tuples([("red", extra)]),
              ),
          ],
          axis=1,
      )
  
      # check that the repr is good
      # make sure that we have a correct sparsified repr
      # e.g. only 1 header of read
      assert str(df2).splitlines()[0].split() == ["red"]
  
      # GH 8017
      # sorting fails after columns added
  
      # construct single-dtype then sort
      result = df.copy().sort_index(axis=1)
      expected = df.iloc[:, [0, 2, 1, 3]]
      tm.assert_frame_equal(result, expected)
  
      result = df2.sort_index(axis=1)
      expected = df2.iloc[:, [0, 2, 1, 4, 3]]
      tm.assert_frame_equal(result, expected)
  
      # setitem then sort
      result = df.copy()
      result[("red", extra)] = "world"
  
      result = result.sort_index(axis=1)
      tm.assert_frame_equal(result, expected)
  
imports: import numpy
  import pytest
  import pandas
  from pandas import CategoricalDtype, CategoricalIndex, DataFrame, IntervalIndex, MultiIndex, RangeIndex, Series, Timestamp
  import pandas._testing
label_desc: Use image node_id 24 for calling the TestDataFrameSortIndex obj's underlying member method code with example usage: obj.test_sort_index_multilevel_repr_8017(gen, extra) without return types