WeightClass::model PHP Method

    public static function model($className = __CLASS__)
    {
        return parent::model($className);
    }

 public function actionUpdate($id)
 {
     $model = new ProductForm();
     if (isset($_POST['ProductForm'])) {
         $model->attributes = $_POST['ProductForm'];
         if ($model->validate()) {
             $model->save();
             $this->redirect(array('index'));
         }
     } else {
         $model->loadDataFromProduct($id);
     }
     $statuses = array(0 => Yii::t('common', 'Disabled'), 1 => Yii::t('common', 'Enabled'));
     $yes_no = array(0 => Yii::t('common', 'No'), 1 => Yii::t('common', 'Yes'));
     $taxClasses = TaxClass::model()->findAll();
     $taxClassesList = array();
     foreach ($taxClasses as $taxClass) {
         $taxClassesList[$taxClass->tax_class_id] = $taxClass->title;
     }
     // TODO: add language
     $stockStatuses = StockStatus::model()->findAll();
     $stockStatusesList = array();
     foreach ($stockStatuses as $stockStatus) {
         $stockStatusesList[$stockStatus->stock_status_id] = $stockStatus->name;
     }
     // TODO: add language
     $weightClasses = WeightClass::model()->findAll();
     $weightClassesList = array();
     foreach ($weightClasses as $weightClass) {
         $weightClassesList[$weightClass->weight_class_id] = $weightClass->description->title;
     }
     // TODO: add language
     $lengthClasses = LengthClass::model()->findAll();
     $lengthClassesList = array();
     foreach ($lengthClasses as $lengthClass) {
         $lengthClassesList[$lengthClass->length_class_id] = $lengthClass->description->title;
     }
     $this->render('update', array('model' => $model, 'statuses' => $statuses, 'taxClasses' => $taxClassesList, 'yes_no' => $yes_no, 'stockStatuses' => $stockStatusesList, 'weightClasses' => $weightClassesList, 'lengthClasses' => $lengthClassesList));
 }