code: def test_sum(self):
      self.assertEqual(self.table.aggregate(Sum("two")), 9)
  
file_path: agate/tests/test_table/test_aggregate.py
imports: from agate import Table
  from agate.aggregations import Count, Sum
  from agate.data_types import Number, Text
  from agate.testcase import AgateTestCase
label_desc: Use image node_id 3 for calling the TestAggregate obj's underlying member method code with example usage: obj.test_sum() without return types