code: def test_preserved_series(self, func):
      s = pd.Series([0, 1], index=["a", "b"]).set_flags(
          allows_duplicate_labels=False
      )
      assert func(s).flags.allows_duplicate_labels is False
  
imports: import operator
  import numpy
  import pytest
  import pandas
  import pandas._testing
label_desc: Use image node_id 2 for calling the TestPreserves obj's underlying member method code with example usage: obj.test_preserved_series(func) without return types