public function addFeature(Feature $fe)
    {
        $db = Loader::db();
        $db->Replace(
           'CollectionVersionFeatures',
           ['cID' => $this->getCollectionID(), 'cvID' => $this->getVersionID(), 'feID' => $fe->getFeatureID()],
           ['cID', 'cvID', 'feID'],
           true
        );
    }