code: def test_union_different_types(index_flat, index_flat2, request):
      # This test only considers combinations of indices
      # GH 23525
      idx1 = index_flat
      idx2 = index_flat2
  
      if (
          not idx1.is_unique
          and not idx2.is_unique
          and idx1.dtype.kind == "i"
          and idx2.dtype.kind == "b"
      ) or (
          not idx2.is_unique
          and not idx1.is_unique
          and idx2.dtype.kind == "i"
          and idx1.dtype.kind == "b"
      ):
          # Each condition had idx[1|2].is_monotonic_decreasing
          # but failed when e.g.
          # idx1 = Index(
          # [True, True, True, True, True, True, True, True, False, False], dtype='bool'
          # )
          # idx2 = Index([0, 0, 1, 1, 2, 2], dtype='int64')
          mark = pytest.mark.xfail(
              reason="GH#44000 True==1", raises=ValueError, strict=False
          )
          request.applymarker(mark)
  
      common_dtype = find_common_type([idx1.dtype, idx2.dtype])
  
      warn = None
      msg = "'<' not supported between"
      if not len(idx1) or not len(idx2):
          pass
      elif (
          idx1.dtype.kind == "c"
          and (not lib.is_np_dtype(idx2.dtype, "iufc"))
      ) or (
          idx2.dtype.kind == "c"
          and (not lib.is_np_dtype(idx1.dtype, "iufc"))
      ):
          # complex objects non-sortable
          warn = RuntimeWarning
      elif (
          isinstance(idx1.dtype, PeriodDtype)
          and isinstance(idx2.dtype, CategoricalDtype)
      ) or (
          isinstance(idx2.dtype, PeriodDtype)
          and isinstance(idx1.dtype, CategoricalDtype)
      ):
          warn = FutureWarning
          msg = r"PeriodDtype\[B\] is deprecated"
          mark = pytest.mark.xfail(
              reason="Warning not produced on all builds",
              raises=AssertionError,
              strict=False,
          )
          request.applymarker(mark)
  
      any_uint64 = np.uint64 in (idx1.dtype, idx2.dtype)
      idx1_signed = is_signed_integer_dtype(idx1.dtype)
      idx2_signed = is_signed_integer_dtype(idx2.dtype)
  
      # Union with a non-unique, non-monotonic index raises error
      # This applies to the boolean index
      idx1 = idx1.sort_values()
      idx2 = idx2.sort_values()
  
      with tm.assert_produces_warning(warn, match=msg):
          res1 = idx1.union(idx2)
          res2 = idx2.union(idx1)
  
      if any_uint64 and (idx1_signed or idx2_signed):
          assert res1.dtype == np.dtype("O")
          assert res2.dtype == np.dtype("O")
      else:
          assert res1.dtype == common_dtype
          assert res2.dtype == common_dtype
  
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 5 for calling a global function with example usage: test_union_different_types(index_flat, index_flat2, request) without return types