InstanceExceptionInvoker

Invoker for instance-bound exception handler methods that declare both an event and a throwable parameter:

fun onFailure(event: E, t: T)

A handler using this signature is selected when:

• the event being processed is an instance of E or any subtype, and

• the thrown exception is an instance of T or any subtype.

This makes it the most specific and expressive form of exception handler, allowing subscribers to handle particular failure modes for particular event types.