def METHOD_NAME(namespace):
    if namespace.system_assigned is None:
        raise InvalidArgumentValueError('Parameter "system-assigned" expected at least one argument.')
    namespace.system_assigned = namespace.system_assigned.strip().lower()
    if namespace.system_assigned.strip().lower() not in (ENABLE_LOWER, DISABLE_LOWER):
        raise InvalidArgumentValueError('Allowed values for "system-assigned" are: {}, {}.'.format(ENABLE_LOWER, DISABLE_LOWER))