Bug 315281 update copyrights for 3.6
bundles/org.eclipse.core.databinding.property/src/org/eclipse/core/internal/databinding/property/set/SimplePropertyObservableSet.java
}
		Set removals = new HashSet(set);
		removals.removeAll(c);
		if (removals.isEmpty())
			return false;
		SetDiff diff = Diffs.createSetDiff(Collections.EMPTY_SET, removals);
		updateSet(set, diff);
		return true;
	}
	public void clear() {
		getterCalled();
		Set set = getSet();
		if (set.isEmpty())
			return;
		SetDiff diff = Diffs.createSetDiff(Collections.EMPTY_SET, set);
		updateSet(set, diff);
	}
	private void notifyIfChanged(SetDiff diff) {
		if (hasListeners()) {
			Set oldSet = cachedSet;
			Set newSet = cachedSet = new HashSet(getSet());
			if (diff == null)
				diff = Diffs.computeSetDiff(oldSet, newSet);
			if (!diff.isEmpty() || stale) {
				stale = false;
				fireSetChange(diff);
			}
		}
	}
	public boolean isStale() {