<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 async def is_anonymous(request):
 """Check if user is anonymous. User is considered anonymous if there is not identity in request. """

    identity_policy = request.config_dict.get(IDENTITY_KEY)
    if identity_policy is None:
        return True
    identity = await identity_policy.identify(request)
    if identity is None:
        return True
    return False