code: @Nonnull
      public static synchronized ScheduledExecutorService get() {
          if (executorService == null) {
              // corePoolSize is set to 10, but will only be created if needed.
              // ScheduledThreadPoolExecutor "acts as a fixed-sized pool using corePoolSize threads"
              // TODO consider also wrapping in ContextResettingExecutorService
               executorService = new ImpersonatingScheduledExecutorService(new ErrorLoggingScheduledThreadPoolExecutor(10, new NamingThreadFactory(new ClassLoaderSanityThreadFactory(new DaemonThreadFactory()), "jenkins.util.Timer")), ACL.SYSTEM);
          }
          return executorService;
      }
docs: Returns the scheduled executor service used by all timed tasks in Jenkins.
  
  @return the single {@link ScheduledExecutorService}.