if (observers == null) observers = new ArrayList(1); if (!observers.contains(o)) observers.add(o);
if (hasObserver(o)) return; if (observers == null) { observers = new Observer[1]; observers[0] = o; } else { Observer n[] = new Observer[observers.length + 1]; System.arraycopy(observers, 0, n, 0, observers.length); n[observers.length] = o; observers = n; }
	public void addObserver(Observer o) {		if (observers == null)			observers = new ArrayList(1);		if (!observers.contains(o))			observers.add(o);	}