public function getVersions()
{
$versionIds = $this->db->fetchCol("SELECT id FROM versions WHERE cid = ? AND ctype='object' ORDER BY `id` DESC", $this->model->getId());
$versions = [];
foreach ($versionIds as $versionId) {
$versions[] = Model\Version::getById($versionId);
}
$this->model->setVersions($versions);
return $versions;
}