docs: public TaskExecutor launchNow(Cron4jTask cron4jTask, LaunchNowOption nowOption) {
          setupLinkedLockIfNeeds();
          synchronized (linkedLock) {
              if (!isStarted()) {
                  throw new IllegalStateException("Scheduler not started");
              }
              return doSpawnExecutor(cron4jTask, OptionalThing.of(nowOption));
          }
      }