func (r *Response) Size() int64 {
	return r.size
}
Size returns the number of bytes written in the *Response
package lars
import (
	"bufio"
	"io"
	"log"
	"net"
	"net/http"
)
type Response struct {
	http.ResponseWriter
	status    int
	size      int64
	committed bool
	context   Context
}
func newResponse(w http.ResponseWriter, context Context) *Response {
	return &Response{ResponseWriter: w, context: context}
}
func (r *Response) SetWriter(w http.ResponseWriter) {
	r.ResponseWriter = w
}
func (r *Response) Writer() http.ResponseWriter {
	return r.ResponseWriter
}
func (r *Response) Header() http.Header {
	return r.ResponseWriter.Header()
}
func (r *Response) WriteHeader(code int) {
	if r.committed {
		log.Println("response already committed")
		return
	}
	r.status = code
	r.ResponseWriter.WriteHeader(code)
	r.committed = true
}
func (r *Response) Write(b []byte) (n int, err error) {
	n, err = r.ResponseWriter.Write(b)
	r.size += int64(n)
	return n, err
}
func (r *Response) WriteString(s string) (n int, err error) {
	n, err = io.WriteString(r.ResponseWriter, s)
	r.size += int64(n)
	return
}
func (r *Response) Flush() {
	r.ResponseWriter.(http.Flusher).Flush()
}
func (r *Response) Hijack() (net.Conn, *bufio.ReadWriter, error) {
	return r.ResponseWriter.(http.Hijacker).Hijack()
}
func (r *Response) CloseNotify() <-chan bool {
	return r.ResponseWriter.(http.CloseNotifier).CloseNotify()
}
func (r *Response) Status() int {
	return r.status
}