code: def test_aggregate_key_name(self):
      tableset = TableSet(
          self.tables.values(), self.tables.keys(), key_name="test"
      )
  
      new_table = tableset.aggregate([("count", Count())])
  
      self.assertIsInstance(new_table, Table)
      self.assertColumnNames(new_table, ("test", "count"))
      self.assertColumnTypes(new_table, [Text, Number])
  
imports: from collections import OrderedDict
  from decimal import Decimal
  from agate import Table, TableSet
  from agate.aggregations import Count, MaxLength, Mean, Min, Sum
  from agate.data_types import Number, Text
  from agate.exceptions import DataTypeError
  from agate.testcase import AgateTestCase
label_desc: Use image node_id 2 for calling the TestAggregate obj's underlying member method code with example usage: obj.test_aggregate_key_name() without return types