public function isInstanceOf( core_kernel_classes_Class $class)
    {
        $returnValue = (bool) false;
        foreach($this->getTypes() as $type){
        	if ($class->equals($type) || $type->isSubClassOf($class)){
        		$returnValue = true;
        		break;
        	}
        }
        return (bool) $returnValue;
    }