Invoked when Tapestry {@linkplain UpdateListenerHub#fireCheckForUpdates() noticesthat the implementation class has changed}. The existing instance is notified, so that it can cleanly shutdown now, before being re-instantiated. This is necessary when the service implementation retains some form of external resources.
In addition, the implementation may request an immediate reload. Normally, reloading of the service is deferred until a method of the proxy object is invoked (this causes the normal just-in-time instantiation of the implementation). When this method returns true, the implementation is re-created immediately. This is most often the case for services that are {@linkplain EagerLoad eagerly loaded} in the first place.
@return true if the service should be reloaded immediately, false if reload should be deferred