code: def test_fillna_categorical_with_new_categories(
      self, fill_value, expected_output
  ):
      # GH#26215
      data = ["a", np.nan, "b", np.nan, np.nan]
      ser = Series(
          Categorical(data, categories=["a", "b", "c", "d", "e"])
      )
      exp = Series(
          Categorical(
              expected_output, categories=["a", "b", "c", "d", "e"]
          )
      )
      fill_value = Series(fill_value)
      result = ser.fillna(fill_value)
      tm.assert_series_equal(result, exp)
  
imports: from datetime import datetime, timedelta, timezone
  import numpy
  import pytest
  import pytz
  from pandas import Categorical, DataFrame, DatetimeIndex, NaT, Period, Series, Timedelta, Timestamp, date_range, isna, timedelta_range
  import pandas._testing
  from pandas.core.arrays import period_array
label_desc: Use image node_id 24 for calling the TestSeriesFillNA obj's underlying member method code with example usage: obj.test_fillna_categorical_with_new_categories(fill_value, expected_output) without return types