don't explicitly nil err
(make happy)
@@ -83,7 +83,7 @@ func (c *Conn) Write(b []byte) (n int, err error) {
// close error, subsequent and concurrent calls will return nil.
// This method is thread-safe.
func (c *Conn) Close() error {
- var err error = nil
+ var err error
c.closeOnce.Do(func() {
if c.done != nil {
c.done()
