TimedObjectInvoker is based on EJB3.0 spec which expected that there will be only one timeout method on a bean. Starting EJB3.1, there can be multiple methods on a bean which can act as timeout invocation methods, due to the autotimer (@Schedule, @Schedules feature). The TimedObjectInvoker's:

void callTimeout(Timer timer) throws Exception;

is no longer sufficient to identify the correct timeout method corresponding to the timer. There now needs to be a way wherein the timer service implementation can pass the information about the timeout method (which will be provided to the timer service implementation when the auto timers are being created).