code: func NewResponse(r *http.Request, contentType string, status int, body string) *http.Response {
  	resp := &http.Response{}
  	resp.Request = r
  	resp.TransferEncoding = r.TransferEncoding
  	resp.Header = make(http.Header)
  	resp.Header.Add("Content-Type", contentType)
  	resp.StatusCode = status
  	resp.Status = http.StatusText(status)
  	buf := bytes.NewBufferString(body)
  	resp.ContentLength = int64(buf.Len())
  	resp.Body = ioutil.NopCloser(buf)
  	return resp
  }
docs: // Will generate a valid http response to the given request the response will have
  // the given contentType, and http status.
  // Typical usage, refuse to process requests to local addresses:
  //
  //	proxy.OnRequest(IsLocalHost()).DoFunc(func(r *http.Request, ctx *goproxy.ProxyCtx) (*http.Request,*http.Response) {
  //		return nil,NewResponse(r,goproxy.ContentTypeHtml,http.StatusUnauthorized,
  //			`<!doctype html><html><head><title>Can't use proxy for local addresses</title></head><body/></html>`)
  //	})