code: public List<String> getCalendarNames(T jedis){
          final Set<String> calendarsSet = jedis.smembers(redisSchema.calendarsSet());
          List<String> calendars = new ArrayList<>(calendarsSet.size());
          for (String group : calendarsSet) {
              calendars.add(redisSchema.calendarName(group));
          }
          return calendars;
      }
docs: Get the names of all of the <code>{@link org.quartz.Calendar}</code> s in the <code>JobStore</code>.
  @param jedis a thread-safe Redis connection
  @return the names of all calendars or an empty list if no calendars exist