code: def test_duplicated_nan_none(keep, expected):
      ser = Series([np.nan, 3, 3, None, np.nan], dtype=object)
  
      result = ser.duplicated(keep=keep)
      expected = Series(expected)
      tm.assert_series_equal(result, expected)
  
file_path: pandas/pandas/tests/series/methods/test_duplicated.py
imports: import numpy
  import pytest
  from pandas import NA, Categorical, Series
  import pandas._testing
label_desc: Use image node_id 2 for calling a global function with example usage: test_duplicated_nan_none(keep, expected) without return types