code: def ci(self):
      categories = list("cab")
      return CategoricalIndex(
          list("aabbca"), categories=categories, ordered=False
      )
  
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 1 for calling the TestAppend obj's underlying member method code with example usage: obj.ci() and returns: CategoricalIndex