Amazon offers AddOn products that can be bough with some other product only. Addon products must be removed from basket if added without the parent product. This type of validation can be done easily by implementing ILineItemValidotr interface.
You can find a test implementation of custom Line Item Validator on Git.
You will require to register new custom validation class implicitly into your container.
It will be helpful if in future versions a generic type can be used rather ValidationIssue Enum in Validate method.
It will be helpful if in future versions a generic type can be used rather ValidationIssue Enum in Validate method.