code: def test_shallow_copy_empty(self):
      # GH#13067
      idx = PeriodIndex([], freq="M")
      result = idx._view()
      expected = idx
  
      tm.assert_index_equal(result, 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 1 for calling the TestShallowCopy obj's underlying member method code with example usage: obj.test_shallow_copy_empty() without return types