code: def test_hour_index(self):
      dt_series = Series(
          date_range(start="2021-01-01", periods=5, freq="h"),
          index=[2, 6, 7, 8, 11],
          dtype="category",
      )
      result = dt_series.dt.hour
      expected = Series(
          [0, 1, 2, 3, 4],
          dtype="int32",
          index=[2, 6, 7, 8, 11],
      )
      tm.assert_series_equal(result, expected)
  
imports: import calendar
  from datetime import date, datetime, time
  import locale
  import unicodedata
  import numpy
  import pytest
  import pytz
  from pandas._libs.tslibs.timezones import maybe_get_tz
  from pandas.errors import SettingWithCopyError
  from pandas.core.dtypes.common import is_integer_dtype, is_list_like
  import pandas
  from pandas import DataFrame, DatetimeIndex, Index, Period, PeriodIndex, Series, TimedeltaIndex, date_range, period_range, timedelta_range
  import pandas._testing
  from pandas.core.arrays import DatetimeArray, PeriodArray, TimedeltaArray
label_desc: Use image node_id 36 for calling the TestSeriesDatetimeValues obj's underlying member method code with example usage: obj.test_hour_index() without return types