code: def test_add_categories(self):
      pidx = pd.CategoricalIndex([1, 2, 3], categories=[3, 2, 1])
      psidx = ps.from_pandas(pidx)
  
      self.assert_eq(pidx.add_categories(4), psidx.add_categories(4))
      self.assert_eq(
          pidx.add_categories([4, 5]), psidx.add_categories([4, 5])
      )
      self.assert_eq(pidx.add_categories([]), psidx.add_categories([]))
  
      self.assertRaises(ValueError, lambda: psidx.add_categories(3))
      self.assertRaises(
          ValueError, lambda: psidx.add_categories([4, 4])
      )
  
imports: import unittest
  import pandas
  from pandas.api.types import CategoricalDtype
  import pyspark.pandas
  from pyspark.loose_version import LooseVersion
  from pyspark.testing.pandasutils import PandasOnSparkTestCase, TestUtils
label_desc: Use image node_id 3 for calling the CategoricalIndexTestsMixin obj's underlying member method code with example usage: obj.test_add_categories() without return types