Bug 184755 [DataBinding] internal tree content provider does not work
I broke the tree content providers while trying to update them to use TreePaths. It would be good to have a working implementation again...
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/observable/set/AbstractObservableSet.java
getterCalled();
		return getWrappedSet().toString();
	}
	protected void getterCalled() {
		ObservableTracker.getterCalled(this);
	}
	public boolean add(Object o) {
		throw new UnsupportedOperationException();
	}
	public boolean addAll(Collection c) {
		throw new UnsupportedOperationException();
	}
	public boolean remove(Object o) {
		throw new UnsupportedOperationException();
	}
	public boolean removeAll(Collection c) {
		throw new UnsupportedOperationException();
	}
	public boolean retainAll(Collection c) {
		throw new UnsupportedOperationException();
	}
	public void clear() {
		throw new UnsupportedOperationException();
	}
	/**
	 * @return Returns the stale state.
	 */
	public boolean isStale() {
		checkRealm();
		return stale;