@@ -21,3 +21,19 @@ func NopWriteCloser(w io.Writer) io.WriteCloser {

 type NopFlusher struct{}

 func (f *NopFlusher) Flush() {}

+

+type writeCloserWrapper struct {

+	io.Writer

+	closer func() error

+}

+

+func (r *writeCloserWrapper) Close() error {

+	return r.closer()

+}

+

+func NewWriteCloserWrapper(r io.Writer, closer func() error) io.WriteCloser {

+	return &writeCloserWrapper{

+		Writer: r,

+		closer: closer,

+	}

+}