code: @Override public synchronized Long sadd(final String key, final String member, final String ... members) throws WrongTypeException {
          checkType(key, "set");
          Long count = 0L;
          if (!setCache.exists(key) || !setCache.get(key).contains(member)) {
              setCache.set(key, member);
              count += 1L;
          }
          for (String memb : members) {
              if (!setCache.exists(key) || !setCache.get(key).contains(memb)) {
                  setCache.set(key, memb);
                  count += 1L;
              }
          }
          if (count > 0L) {
              keyModified(key);
          }
          return count;
      }
docs: /* IRedisSet implementations