| ⇢ | A | SubstituteOrder added | 
| ⇢ | A | SubstituteOrder::createSubstituteOrder() added | |
| ⇢ | A | Database::getSubstituteOrderIncrementId() added | |
| ⇢ | A | SubstituteOrder::updateCheckoutSession() added | |
| ⇢ | A | SubstituteOrder::__construct() added | |
| ⇢ | A | SubstituteOrder::handleTransactionStatus() added | |
| A | ↛ | Returned::createSubstituteOrder() removed | |
| A | ↛ | Returned::handleTransactionStatus() removed |