From Xojo Documentation
The Raise statement is used to raise an exception to the next level in the calling chain.
Expression must evaluate to an object that is a subclass of RuntimeException — and will be the object that is passed to any exception handlers.
You can create your own subclasses of RuntimeException and use Raise to raise them for error conditions.
Manually raise an OutOfBoundsException:
Raise your own RuntimeException subclass. In this code, ParseException is a class added to the project and is a subclass of RuntimeException: