can you write this code in scala? public abstract class Loggable $\{$

private List observers $=$ new ArrayList$<>()$;

private long timestamp;

public void attach$($LoggingObserver observer$)\{$

observers.add$($observer$)$;

$\}$

public void notifyAllObservers$()\{$

timestamp $=$ System.currentTimeMillis$()$;

for $($LoggingObserver observer : observers$)\{$

observer.update$($this$,$ timestamp$)$;

$\}$

$\}$

$\}$