Bug 175418 [DataBinding] TreePath moved to internal package
In M5 TreePath moved from org.eclipse.core.databinding.observable.tree.TreePath to org.eclipse.core.internal.databinding.observable.tree.TreePath Non Internal Public interfaces such as: org.eclipse.core.databinding.observable.tree.IOrderedTreeProvider and org.eclipse.core.databinding.observable.tree.IUnorderedTreeProvider depend on this class.
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/internal/viewers/OrderedTreeContentProvider.java
/**
		 */
		protected KnownElementsSet() {
			super(provider.getRealm());
		}
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.jface.internal.databinding.provisional.observable.set.AbstractObservableSet#getWrappedSet()
		 */
		protected Set getWrappedSet() {
			return mapElementToTreeNode.keySet();
		}
		void doFireDiff(Set added, Set removed) {
			fireSetChange(Diffs.createSetDiff(added, removed));
		}
		void doFireStale(boolean isStale) {
			if (isStale) {
				fireStale();
			} else {
				fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET,
						Collections.EMPTY_SET));
			}
		}
		public Object getElementType() {
			return Object.class;
		}
		protected void fireSetChange(SetDiff diff) {
			super.fireSetChange(diff);