public static void assertJobManagerIdle() {
   final IJobManager jm = Job.getJobManager();
   if (jm.isIdle()) {
     return; // OK!
   }
   // Make a nice message listing all the jobs and their present state.
   Job[] allJobs = jm.find(null);
   StringBuffer msg = new StringBuffer("JobManager not idle: \n");
   for (Job job : allJobs) {
     msg.append("   Job: " + job.getName() + " State: " + stateString(job) + "\n");
   }
   throw new AssertionFailedError(msg.toString());
 }