title: do not know how to remove sqlalchemy 1.4 warning about cache_ok
body: <p>I am using <code>sqlalchemy</code> 1.4.17 with postgres and have a <code>pytest-asyncio</code> test which calls a function that creates a record that contains a uuid.</p>
  <pre><code>
  async def create_user(session: AsyncSession, input_user_data):
       new_user = model.User(**dict(input_user_data))
       session.add(new_user)
       await session.commit()
  </code></pre>
  <pre><code>class User(Base):
      __tablename__ = &quot;user&quot;
      id = Column(GUID, primary_key=True,
                  server_default=DefaultClause(text(&quot;gen_random_uuid()&quot;)))
  
  </code></pre>
  <p>and it runs ok, but creates a warning</p>
  <pre><code>  sys:1: SAWarning: TypeDecorator GUID() will not produce a cache key because the ``cache_ok`` flag is not set to True.  Set this flag to True if this type object's state is safe to use in a cache key, or False to disable this warning.
  </code></pre>
  <p>and don't understand how to silence it. any help is appreciated!</p>