final protected function setCollectionClass($class)
    {
        try {
            $this->collectionClass = new StringType($class);
        } catch (TypeValidationException $e) {
            $this->collectionClass = CollectionConstants::_UNMAPPABLE_CLASS;
        } catch (ValueOutOfBoundsException $e) {
            $this->collectionClass = CollectionConstants::_UNMAPPABLE_CLASS;
        }
    }