code: def test_groupby_rolling_resulting_multiindex2(self):
      # grouping by 2 columns -> 3-level MI as result
      df = DataFrame(
          {"a": np.arange(12.0), "b": [1, 2] * 6, "c": [1, 2, 3, 4] * 3}
      )
      result = df.groupby(["b", "c"]).rolling(2).sum()
      expected_index = MultiIndex.from_tuples(
          [
              (1, 1, 0),
              (1, 1, 4),
              (1, 1, 8),
              (1, 3, 2),
              (1, 3, 6),
              (1, 3, 10),
              (2, 2, 1),
              (2, 2, 5),
              (2, 2, 9),
              (2, 4, 3),
              (2, 4, 7),
              (2, 4, 11),
          ],
          names=["b", "c", None],
      )
      tm.assert_index_equal(result.index, expected_index)
  
imports: import numpy
  import pytest
  from pandas import DataFrame, DatetimeIndex, Index, MultiIndex, Series, Timestamp, date_range, to_datetime
  import pandas._testing
  from pandas.api.indexers import BaseIndexer
  from pandas.core.groupby.groupby import get_groupby
label_desc: Use image node_id 31 for calling the TestRolling obj's underlying member method code with example usage: obj.test_groupby_rolling_resulting_multiindex2() without return types