code: def test_multiindex_repeated_keys(self):
      # GH19414
      tm.assert_series_equal(
          Series([1, 2], MultiIndex.from_arrays([["a", "b"]])).loc[
              ["a", "a", "b", "b"]
          ],
          Series(
              [1, 1, 2, 2],
              MultiIndex.from_arrays([["a", "a", "b", "b"]]),
          ),
      )
  
imports: import numpy
  import pytest
  import pandas._libs.index
  from pandas.errors import PerformanceWarning
  import pandas
  from pandas import CategoricalDtype, DataFrame, Index, MultiIndex, Series
  import pandas._testing
  from pandas.core.arrays.boolean import BooleanDtype
label_desc: Use image node_id 12 for calling the TestMultiIndexBasic obj's underlying member method code with example usage: obj.test_multiindex_repeated_keys() without return types