public function targetStarted(BuildEvent $event)
    {
        $target = $event->getTarget();

        $targetElement = $this->doc->createElement(XmlLogger::TARGET_TAG);
        $targetElement->setAttribute(XmlLogger::NAME_ATTR, $target->getName());

        $this->timesStack[] = Phing::currentTimeMillis();
        $this->elementStack[] = $targetElement;
    }