code: def test_server_default_onupdate(self):
      text = (
          "A column with an Identity object cannot specify a "
          "server_default or a server_onupdate argument"
      )
  
      def fn(**kwargs):
          Table(
              "t",
              MetaData(),
              Column("y", Integer, Identity(), **kwargs),
          )
  
      assert_raises_message(
          ArgumentError, text, fn, server_default="42"
      )
      assert_raises_message(
          ArgumentError, text, fn, server_onupdate="42"
      )
  
imports: import re
  from sqlalchemy import Column
  from sqlalchemy import Identity
  from sqlalchemy import Integer
  from sqlalchemy import MetaData
  from sqlalchemy import Sequence
  from sqlalchemy import Table
  from sqlalchemy import testing
  from sqlalchemy.engine import URL
  from sqlalchemy.exc import ArgumentError
  from sqlalchemy.schema import CreateTable
  from sqlalchemy.testing import assert_raises_message
  from sqlalchemy.testing import fixtures
  from sqlalchemy.testing import is_
  from sqlalchemy.testing import is_not_
label_desc: Use image node_id 1 for calling the IdentityTest obj's underlying member method code with example usage: obj.test_server_default_onupdate() without return types