code: def test_aggregate(self):
      import pandas as pd
  
      t = self.t_env.from_elements(
          [(1, 2, 3), (2, 1, 3), (1, 5, 4), (1, 8, 6), (2, 3, 4)],
          DataTypes.ROW(
              [
                  DataTypes.FIELD("a", DataTypes.BIGINT()),
                  DataTypes.FIELD("b", DataTypes.SMALLINT()),
                  DataTypes.FIELD("c", DataTypes.INT()),
              ]
          ),
      )
  
      function = CountAndSumAggregateFunction()
      agg = udaf(
          function,
          result_type=function.get_result_type(),
          accumulator_type=function.get_accumulator_type(),
          name=str(function.__class__.__name__),
      )
      result = (
          t.group_by(t.a)
          .aggregate(agg.alias("c", "d"))
          .select(t.a, t.c, expr.col("d"))
          .to_pandas()
      )
      assert_frame_equal(
          result.sort_values("a").reset_index(drop=True),
          pd.DataFrame(
              [[1, 3, 15], [2, 2, 4]], columns=["a", "c", "d"]
          ),
      )
  
imports: import unittest
  from pandas.testing import assert_frame_equal
  from pyflink.common import Row
  from pyflink.table import expressions, ListView
  from pyflink.table.types import DataTypes
  from pyflink.table.udf import udf, udtf, udaf, AggregateFunction, TableAggregateFunction, udtaf
  from pyflink.testing import source_sink_utils
  from pyflink.testing.test_case_utils import PyFlinkBatchTableTestCase, PyFlinkStreamTableTestCase
label_desc: Use image node_id 1 for calling the StreamRowBasedOperationITTests obj's underlying member method code with example usage: obj.test_aggregate() without return types