log/log.go
func (t *Target) SetLogger(l Logger) {
	t.mut.Lock()
	defer t.mut.Unlock()
	t.logger = l
}
func (t *Target) SetLogger(l Logger) {
	t.mut.Lock()
	defer t.mut.Unlock()
	t.logger = l
}
// SetLogger defines a new logger for the current target.
//
// See the builtin log package for more details.