code: def test_strftime_period_days(self, using_infer_string):
      period_index = period_range("20150301", periods=5)
      result = period_index.strftime("%Y/%m/%d")
      expected = Index(
          [
              "2015/03/01",
              "2015/03/02",
              "2015/03/03",
              "2015/03/04",
              "2015/03/05",
          ],
          dtype="=U10",
      )
      if using_infer_string:
          expected = expected.astype("string[pyarrow_numpy]")
      tm.assert_index_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 23 for calling the TestSeriesDatetimeValues obj's underlying member method code with example usage: obj.test_strftime_period_days(using_infer_string) without return types