code: public String type() {
  		try {
  			if(isCluster(groupName)){
  				return getBinaryJedisClusterCommands(groupName).type(keyBytes);
  			}
  			return getBinaryJedisCommands(groupName).type(keyBytes);
  		} finally {
  			getJedisProvider(groupName).release();
  		}
  
  	}
docs: 返回 key 所储存的值的类型。
  
  @param keyBytes
  @return none (key不存在)
  
  string (字符串)
  
  list (列表)
  
  set (集合)
  
  zset (有序集)
  
  hash (哈希表)