public function resetAttributes(){
        $this->attributes = array();
        foreach($this->getUsedAttributes() as $attributeClass){
            if(class_exists($attributeClass) && is_subclass_of($attributeClass, 'oat\\taoQtiItem\\model\\qti\\attribute\\Attribute')){
                $attribute = new $attributeClass();
                $this->attributes[$attribute->getName()] = $attribute;
            }else{
                common_Logger::w('attr does not exists '.$attributeClass);
            }
        }
    }