code: def test_groupby_split_out_multiindex(agg_func):
      df = cudf.DataFrame(
          {
              "a": np.random.randint(0, 10, 100),
              "b": np.random.randint(0, 5, 100),
              "c": np.random.random(100),
          }
      )
      ddf = dask_cudf.from_cudf(df, 5)
      pddf = dd.from_pandas(df.to_pandas(), 5)
      gr = agg_func(ddf.groupby(["a", "b"]))
      pr = agg_func(pddf.groupby(["a", "b"]))
      dd.assert_eq(gr.compute(), pr.compute())
  
imports: import numpy
  import pandas
  import pytest
  import dask
  from dask import dataframe
  from dask.utils_test import hlg_layer
  import cudf
  import dask_cudf
  from dask_cudf.groupby import OPTIMIZED_AGGS, _aggs_optimized
label_desc: Use image node_id 13 for calling a global function with example usage: test_groupby_split_out_multiindex(agg_func) without return types