code: def test_intersection_difference_match_empty(self, index, sort):
      # GH#20040
      # Test that the intersection of an index with an
      # empty index produces the same index as the difference
      # of an index with itself.  Test for all types
      if not index.is_unique:
          pytest.skip("Not relevant because index is not unique")
      inter = index.intersection(index[:0])
      diff = index.difference(index, sort=sort)
      tm.assert_index_equal(inter, diff, exact=True)
  
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 13 for calling the TestSetOps obj's underlying member method code with example usage: obj.test_intersection_difference_match_empty(index, sort) without return types