code: def test_append_non_categories(self, ci):
      # invalid objects -> cast to object via concat_compat
      result = ci.append(Index(["a", "d"]))
      expected = Index(["a", "a", "b", "b", "c", "a", "a", "d"])
      tm.assert_index_equal(result, expected, exact=True)
  
file_path: pandas/pandas/tests/indexes/categorical/test_append.py
imports: import pytest
  from pandas import CategoricalIndex, Index
  import pandas._testing
label_desc: Use image node_id 6 for calling the TestAppend obj's underlying member method code with example usage: obj.test_append_non_categories(ci) without return types