if err != nil{
            fmt.Println(err)
    }
var dat2 map[string]interface{}
    if err := json.Unmarshal(jsonStr,&dat2);err == nil{
        fmt.Println("userinfo")
        fmt.Println(dat2)
    }
    persistent_code := data2["persistent_code"]
//name := dat2["user_info"].(map[string]interface{})["nick"]
    //openid := dat2["user_info"].(map[string]interface{})["openid"]