code: def test_loc_getitem_listlike_unused_category_raises_keyerror(self):
      # key that is an *unused* category raises
      index = CategoricalIndex(
          ["a", "b", "a", "c"], categories=list("abcde")
      )
      df = DataFrame(
          {"A": [1, 2, 3, 4], "B": [5, 6, 7, 8]}, index=index
      )
  
      with pytest.raises(KeyError, match="e"):
          # For comparison, check the scalar behavior
          df.loc["e"]
  
      with pytest.raises(
          KeyError, match=re.escape("['e'] not in index")
      ):
          df.loc[["a", "e"]]
  
imports: import re
  import numpy
  import pytest
  import pandas.util._test_decorators
  import pandas
  from pandas import Categorical, CategoricalDtype, CategoricalIndex, DataFrame, Index, Interval, Series, Timedelta, Timestamp, option_context
  import pandas._testing
label_desc: Use image node_id 15 for calling the TestCategoricalIndex obj's underlying member method code with example usage: obj.test_loc_getitem_listlike_unused_category_raises_keyerror() without return types