code: def test_index_object_dtype(self, values_constructor):
      # Index(periods, dtype=object) is an Index (not an PeriodIndex)
      periods = [
          Period("2011-01", freq="M"),
          NaT,
          Period("2011-03", freq="M"),
      ]
      values = values_constructor(periods)
      result = Index(values, dtype=object)
  
      assert type(result) is Index
      tm.assert_numpy_array_equal(result.values, np.array(values))
  
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 5 for calling the TestPeriodIndex obj's underlying member method code with example usage: obj.test_index_object_dtype(values_constructor) without return types