public function get($objectType)
    {
        do {
            if (isset($this->permissionCollections[$objectType])) {
                return $this->permissionCollections[$objectType];
            }
            $actualObjectType = $objectType;
            $objectType = get_parent_class($objectType);
        } while ($objectType !== false);

        throw new InvalidArgumentException("No permissions for type $actualObjectType found.");
    }