code: @Override
      public int getNumberOfJobs() throws JobPersistenceException {
          return  doWithLock(new LockCallback<Integer>() {
              @Override
              public Integer doWithLock(JedisCommands jedis) throws JobPersistenceException {
                  return storage.getNumberOfJobs(jedis);
              }
          }, "Could not get number of jobs.");
      }
docs: Get the number of <code>{@link org.quartz.Job}</code> s that are
  stored in the <code>JobsStore</code>.