function processFile($token, $file)
	{
		// Why not in one condition?
		// @see http://forum.nettephp.com/cs/viewtopic.php?pid=29556#p29556
		if (!$file instanceof FileUpload) {
			return false;
		}

		/* @var $validateCallback Callback */
		$validateCallback = MultipleFileUpload::$validateFileCallback;

		/* @var $isValid bool */
		$isValid = $validateCallback->invoke($file);

		if ($isValid) {
			MultipleFileUpload::getQueuesModel()
				->getQueue($token)
				->addFile($file);
		}
		return $isValid;
	}