Crm::getActivity

static function getActivity(VolumeFragment $fragment)
{
	if($fragment->getIndicatorType() == VolumeFile::className())
	{
		$file = $fragment->getFolder();
		if (!$file instanceof DiskFile)
		{
			throw new ArgumentTypeException('Fragment must be subclass of '.DiskFile::className());
		}

		return $file->getOriginalName();
	}

	return parent::getTitle($fragment);
}