code: @Nullable
      public static ScheduledExecutorService getTtlScheduledExecutorService(@Nullable ScheduledExecutorService scheduledExecutorService) {
          if (TtlAgent.isTtlAgentLoaded() || scheduledExecutorService == null || scheduledExecutorService instanceof TtlEnhanced) {
              return scheduledExecutorService;
          }
          return new ScheduledExecutorServiceTtlWrapper(scheduledExecutorService);
      }
docs: {@link TransmittableThreadLocal} Wrapper of {@link ScheduledExecutorService},
  transmit the {@link TransmittableThreadLocal} from the task submit time of {@link Runnable} or {@link java.util.concurrent.Callable}
  to the execution time of {@link Runnable} or {@link java.util.concurrent.Callable}.