code: def test_union_same_value_duplicated_in_both():
      # GH#36289
      a = Index([0, 0, 1])
      b = Index([0, 0, 1, 2])
      result = a.union(b)
      expected = Index([0, 0, 1, 2])
      tm.assert_index_equal(result, expected)
  
imports: from datetime import datetime
  import operator
  import numpy
  import pytest
  from pandas._libs import lib
  from pandas.core.dtypes.cast import find_common_type
  from pandas import CategoricalDtype, CategoricalIndex, DatetimeTZDtype, Index, MultiIndex, PeriodDtype, RangeIndex, Series, Timestamp
  import pandas._testing
  from pandas.api.types import is_signed_integer_dtype, pandas_dtype
label_desc: Use image node_id 14 for calling a global function with example usage: test_union_same_value_duplicated_in_both() without return types