@@ -23,8 +23,8 @@ func NewOutput() *Output {

 // Return true if something was written on this output

 func (o *Output) Used() bool {

-	o.Mutex.Lock()

-	defer o.Mutex.Unlock()

+	o.Lock()

+	defer o.Unlock()

 	return o.used

 }

@@ -32,8 +32,8 @@ func (o *Output) Used() bool {

 // to the output will be written to the new destination in addition to all the others.

 // This method is thread-safe.

 func (o *Output) Add(dst io.Writer) {

-	o.Mutex.Lock()

-	defer o.Mutex.Unlock()

+	o.Lock()

+	defer o.Unlock()

 	o.dests = append(o.dests, dst)

 }

@@ -42,8 +42,8 @@ func (o *Output) Add(dst io.Writer) {

 // destination in addition to all the others. This method is thread-safe.

 func (o *Output) Set(dst io.Writer) {

 	o.Close()

-	o.Mutex.Lock()

-	defer o.Mutex.Unlock()

+	o.Lock()

+	defer o.Unlock()

 	o.dests = []io.Writer{dst}

 }

@@ -96,8 +96,8 @@ func (o *Output) AddString(dst *string) error {

 // Write writes the same data to all registered destinations.

 // This method is thread-safe.

 func (o *Output) Write(p []byte) (n int, err error) {

-	o.Mutex.Lock()

-	defer o.Mutex.Unlock()

+	o.Lock()

+	defer o.Unlock()

 	o.used = true

 	var firstErr error

 	for _, dst := range o.dests {

@@ -113,8 +113,8 @@ func (o *Output) Write(p []byte) (n int, err error) {

 // AddTail and AddString tasks to complete.

 // The Close method of each destination is called if it exists.

 func (o *Output) Close() error {

-	o.Mutex.Lock()

-	defer o.Mutex.Unlock()

+	o.Lock()

+	defer o.Unlock()

 	var firstErr error

 	for _, dst := range o.dests {

 		if closer, ok := dst.(io.WriteCloser); ok {