code: def test_intersection_equal_duplicates(self):
      # GH#38302
      idx = period_range("2011-01-01", periods=2)
      idx_dup = idx.append(idx)
      result = idx_dup.intersection(idx_dup)
      tm.assert_index_equal(result, idx)
  
file_path: pandas/pandas/tests/indexes/period/test_setops.py
imports: import numpy
  import pytest
  import pandas
  from pandas import PeriodIndex, date_range, period_range
  import pandas._testing
label_desc: Use image node_id 7 for calling the TestPeriodIndex obj's underlying member method code with example usage: obj.test_intersection_equal_duplicates() without return types