fixup! export: don't call IsValid separately

conn.go

@@ -563,15 +563,17 @@ func (conn *Conn) send(ctx context.Context, msg *Message, ch chan *Call) *Call {
 			<-ctx.Done()
 			conn.calls.handleSendError(msg, ctx.Err())
 		}()
-		conn.sendMessageAndIfClosed(msg, func() {
+		// error is handled in handleSendError
+		_ = conn.sendMessageAndIfClosed(msg, func() {
 			conn.calls.handleSendError(msg, ErrClosed)
 			canceler()
 		})
 	} else {
 		canceler()
 		call = &Call{Err: nil, Done: ch}
 		ch <- call
-		conn.sendMessageAndIfClosed(msg, func() {
+		// error is handled in handleSendError
+		_ = conn.sendMessageAndIfClosed(msg, func() {
 			call = &Call{Err: ErrClosed}
 		})
 	}
@@ -605,7 +607,8 @@ func (conn *Conn) sendError(err error, dest string, serial uint32) {
 	if len(e.Body) > 0 {
 		msg.Headers[FieldSignature] = MakeVariant(SignatureOf(e.Body...))
 	}
-	conn.sendMessageAndIfClosed(msg, nil)
+	// not much we can do to handle a possible error here
+	_ = conn.sendMessageAndIfClosed(msg, nil)
 }
 
 // sendReply creates a method reply message corresponding to the parameters and
@@ -622,7 +625,8 @@ func (conn *Conn) sendReply(dest string, serial uint32, values ...interface{}) {
 	if len(values) > 0 {
 		msg.Headers[FieldSignature] = MakeVariant(SignatureOf(values...))
 	}
-	conn.sendMessageAndIfClosed(msg, nil)
+	// not much we can do to handle a possible error here
+	_ = conn.sendMessageAndIfClosed(msg, nil)
 }
 
 // AddMatchSignal registers the given match rule to receive broadcast