code: def test_set_categories_private(self):
      cat = Categorical(
          ["a", "b", "c"], categories=["a", "b", "c", "d"]
      )
      cat._set_categories(["a", "c", "d", "e"])
      expected = Categorical(["a", "c", "d"], categories=list("acde"))
      tm.assert_categorical_equal(cat, expected)
  
      # fastpath
      cat = Categorical(
          ["a", "b", "c"], categories=["a", "b", "c", "d"]
      )
      cat._set_categories(["a", "c", "d", "e"], fastpath=True)
      expected = Categorical(["a", "c", "d"], categories=list("acde"))
      tm.assert_categorical_equal(cat, expected)
  
imports: import re
  import numpy
  import pytest
  from pandas.compat import PY311
  from pandas import Categorical, CategoricalIndex, DataFrame, Index, Series, StringDtype
  import pandas._testing
  from pandas.core.arrays.categorical import recode_for_categories
label_desc: Use image node_id 16 for calling the TestCategoricalAPI obj's underlying member method code with example usage: obj.test_set_categories_private() without return types