Response header

How do i get "response header" like `Content-Encoding` ? I need to extract gzip response.

I've used code like this before for http 
```go
if resp.Header.Get("Content-Encoding") == "gzip" {
    // resp.Header.Del("Content-Length")
    zr, err := gzip.NewReader(resp.Body)
    if err != nil {
        return nil, err
    }
    resp.Body = gzreadCloser{zr, resp.Body}
}
```