ResposeWriter / Write的错误处理

I am using osin, Go Lang oAuth Server to try and build a oAuth sever.

So I have used, or i am trying to use the complete example given, to give me a good place to start playing with the code to see what I can do.

However, I have a lot of errors with the file. Now most seem to be about error checking and i have seem to fix them (I am using Visual Code, which as very good Go Lang support). However, no matter what I try I cant seem to fix the error handling for w.Write,

http.HandleFunc("/appauth/code", func(w http.ResponseWriter, r *http.Request) {
    err := r.ParseForm() //*1 
    if err != nil {
        log.Panic(err)
    }

    code := r.Form.Get("code")

    w.Write([]byte("<html><body>")) *2

*1 - This was also missing an error and found my understanding this is how that is meant to be dealt with, please tell me if I am wrong?

*2 - With this I am getting, a errors unhandled call within Visual Code, and no matter how I try to deal with it, it will not work?

This is what I have tried,

err := w.Write([]byte("<html><body>"))

w.Write([]byte("<html><body>") (int, error) ) <- the Write seems to return an int and error?

So I am not sure how to deal with this type of error?

Discard the int if you don't need it:

_, err := w.Write([]byte("<html><body>"))