func (l *Logger) SetBackend(backend LeveledBackend) {
	l.backend = backend
	l.haveBackend = true
}
func (l *Logger) SetBackend(backend LeveledBackend) {
	l.backend = backend
	l.haveBackend = true
}
func ( l * Logger ) SetBackend ( backend LeveledBackend ) { l . backend = backend l . haveBackend = true }
// SetBackend overrides any previously defined backend for this logger.
SetBackend overrides any previously defined backend for this logger .