code: public long count(){
          try {   
          	long count = 0;
          	if(isCluster(groupName)){
          		count = getBinaryJedisClusterCommands(groupName).zcard(keyBytes);
          	}else{
          		count = getBinaryJedisCommands(groupName).zcard(keyBytes);
          	}
  			return count;
      	} finally{
  			getJedisProvider(groupName).release();
  		}
  	}
docs: 查询集合成员数量
  @return