code: def test_join_hierarchical_mixed_raises(self):
      # GH 2024
      # GH 40993: For raising, enforced in 2.0
      df = DataFrame([(1, 2, 3), (4, 5, 6)], columns=["a", "b", "c"])
      new_df = df.groupby(["a"]).agg({"b": ["mean", "sum"]})
      other_df = DataFrame(
          [(1, 2, 3), (7, 10, 6)], columns=["a", "b", "d"]
      )
      other_df.set_index("a", inplace=True)
      # GH 9455, 12219
      with pytest.raises(
          pd.errors.MergeError,
          match="Not allowed to merge between different levels",
      ):
          merge(new_df, other_df, left_index=True, right_index=True)
  
imports: import re
  import numpy
  import pytest
  import pandas.util._test_decorators
  import pandas
  from pandas import Categorical, DataFrame, Index, MultiIndex, Series, Timestamp, bdate_range, concat, merge, option_context
  import pandas._testing
label_desc: Use image node_id 27 for calling the TestJoin obj's underlying member method code with example usage: obj.test_join_hierarchical_mixed_raises() without return types