lib/Model/OrderItem.php
public function getTypeAllowableValues()
    {
        return array(
            self::TYPE_SKU,
            self::TYPE_TAX,
            self::TYPE_SHIPPING,
            self::TYPE_DISCOUNT,
            self::TYPE_STORE_CREDIT,
        );
    }
public function getTypeAllowableValues()
    {
        return array(
            self::TYPE_SKU,
            self::TYPE_TAX,
            self::TYPE_SHIPPING,
            self::TYPE_DISCOUNT,
            self::TYPE_STORE_CREDIT,
        );
    }
Gets allowable values of the enum
@return string[]