| AddOnValidationLibrary | validates the add ons |
| OrderValidationLibrary | Validates the order and execute changes inside order objects if it is necessary, handle changes in order. |
| PaymentValidationLibrary | TODO: at - this "library" could be a single responsibility class validate of payment method id, payment surcharge, payment target |
| PositionValidationLibrary | validates one position |
| ShipmentValidationLibrary | new class ShipmentValidationLibrary |
| ShippingPartsValidationLibrary | |
| TeamDataValidationLibrary | |
| UserDataValidationLibrary | contains functions that validate user data |