code: def test_cython_agg_return_dict():
      # GH 16741
      df = DataFrame(
          {
              "A": [
                  "foo",
                  "bar",
                  "foo",
                  "bar",
                  "foo",
                  "bar",
                  "foo",
                  "foo",
              ],
              "B": [
                  "one",
                  "one",
                  "two",
                  "three",
                  "two",
                  "two",
                  "one",
                  "three",
              ],
              "C": np.random.default_rng(2).standard_normal(8),
              "D": np.random.default_rng(2).standard_normal(8),
          }
      )
  
      ts = df.groupby("A")["B"].agg(
          lambda x: x.value_counts().to_dict()
      )
      expected = Series(
          [
              {"two": 1, "one": 1, "three": 1},
              {"two": 2, "one": 2, "three": 1},
          ],
          index=Index(["bar", "foo"], name="A"),
          name="B",
      )
      tm.assert_series_equal(ts, expected)
  
imports: import numpy
  import pytest
  from pandas.core.dtypes.common import is_float_dtype, is_integer_dtype
  import pandas
  from pandas import DataFrame, Index, NaT, Series, Timedelta, Timestamp, bdate_range
  import pandas._testing
  import pandas.core.common
label_desc: Use image node_id 6 for calling a global function with example usage: test_cython_agg_return_dict() without return types