public function attributeLabels()
{
return array('product_discount_id' => 'Product Discount', 'product_id' => 'Product', 'customer_group_id' => 'Customer Group', 'quantity' => 'Quantity', 'priority' => 'Priority', 'price' => 'Price', 'date_start' => 'Date Start', 'date_end' => 'Date End');
}