### Question:
VmPauseMonitor { public void start() { log.debug( "Starting VM pause monitor" ); checkState( job == null, "VM pause monitor is already started" ); job = requireNonNull( jobScheduler.schedule( Group.VM_PAUSE_MONITOR, this::run ) ); } VmPauseMonitor( Duration measureInterval, Duration stallAlertThreshold, Log log, JobScheduler jobScheduler, Consumer<VmPauseInfo> listener ); void start(); void stop();  }### Answer:
@Test( expected = IllegalStateException.class ) public void testFailOnDoubleStart() { monitor.start(); monitor.start(); }