public function getInjectablePropertiesByConstructor() {
    	if ($this->injectablePropertiesByConstructor === null) {
	    	$moufProperties = array();
	    	$constructor = $this->getConstructor();
	    	if ($constructor != null) {
	    		foreach($constructor->getParameters() as $parameter) {
	    			$propertyDescriptor = new MoufPropertyDescriptor($parameter);
	    			$moufProperties[$propertyDescriptor->getName()] = $propertyDescriptor;
	    		}
	    	}
	    	$this->injectablePropertiesByConstructor = $moufProperties;
    	}
    	return $this->injectablePropertiesByConstructor;
    }