code: @Override
      public List<String> getCalendarNames() throws JobPersistenceException {
          return doWithLock(new LockCallback<List<String>>() {
              @Override
              public List<String> doWithLock(JedisCommands jedis) throws JobPersistenceException {
                  return storage.getCalendarNames(jedis);
              }
          }, "Could not retrieve calendar names.");
      }
docs: Get the names of all of the <code>{@link org.quartz.Calendar}</code> s
  in the <code>JobStore</code>.
  <p/>
  <p>
  If there are no Calendars in the given group name, the result should be
  a zero-length array (not <code>null</code>).
  </p>