getTimerService() is method from EJBContext used to get TimerService object.
It can not be invoked from
1) setSessionContext - becoz EJBContext/SessionContext is not initialised for use.
2) ejbCreate - becoz dependency injection methods (e.g. setSessionContext) are invoked after this method
3) ejbRemove - becoz there is no way to ensure when this method gets called
by the container in case of stateless bean. So not useful to get timer service instance.