code: def test_constructor_freq_combined(self):
      for freq in ["1D1h", "1h1D"]:
          pidx = PeriodIndex(["2016-01-01", "2016-01-02"], freq=freq)
          expected = PeriodIndex(
              ["2016-01-01 00:00", "2016-01-02 00:00"], freq="25h"
          )
      for freq in ["1D1h", "1h1D"]:
          pidx = period_range(start="2016-01-01", periods=2, freq=freq)
          expected = PeriodIndex(
              ["2016-01-01 00:00", "2016-01-02 01:00"], freq="25h"
          )
          tm.assert_index_equal(pidx, expected)
  
imports: import numpy
  import pytest
  from pandas._libs.tslibs.period import IncompatibleFrequency
  from pandas.core.dtypes.dtypes import PeriodDtype
  from pandas import Index, NaT, Period, PeriodIndex, Series, date_range, offsets, period_range
  import pandas._testing
  from pandas.core.arrays import PeriodArray
label_desc: Use image node_id 26 for calling the TestPeriodIndex obj's underlying member method code with example usage: obj.test_constructor_freq_combined() without return types