public function update(EntityInterface $user)
    {
        if (!is_a($user, self::ACCESS_ENTITY_TYPE)) {
            throw new Exception('The given entity (' . get_class($user) . ') is not compatible with this data source (' . self::class . '.');
        }
        
        // If the uuid does not exists we cannot update the user
        if (!$this->accessControlManager->hasAccessEntityForUuid(self::ACCESS_ENTITY_TYPE, $user->getUuid())) {
            throw new Exception('Cannot update the user. User does not exist.');
        }
        
        // Add the access entity
        return $this->accessControlManager->updateAccessEntity($user);
    }