code: public long add(double score, Object value){
          try {   
          	long result = 0;
          	if(isCluster(groupName)){
          		result = getBinaryJedisClusterCommands(groupName).zadd(keyBytes, score, valueSerialize(value));
          	}else{
          		result = getBinaryJedisCommands(groupName).zadd(keyBytes, score, valueSerialize(value));
          	}
          	//设置超时时间
          	if(result > 0)setExpireIfNot(expireTime);
  			return result;
      	} finally{
  			getJedisProvider(groupName).release();
  		}
  	}
docs: 新增元素
  @param score 权重
  @param value  元素
  @return