I think this should work:

    class MockTimeService implements TimeService { 
       public theTime; 
       public long time() { return theTime; }
       ...
    }
    class TickInterceptor extends BaseCustomInterceptor {
       TimeService timeService;
       void setTimeService(TimeService timeService) { this.timeService = timeService; }
       Object handleDefault(...) { timeService.theTime++; }
       ...
    }