Bug 89606 [Viewers] Remove protected API added to support prototype of grouping by working sets
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* @param lastInsertion
	 *            the start index to start search for position from this allows
	 *            optimizing search for multiple elements that are sorted
	 *            themselves.
	 * @param element
	 *            element to find position for.
	 * @param parentPath
	 *            the tree path for the element's parent or <code>null</code>
	 *            if the element is a root element or the sorter is not a
	 *            {@link TreePathViewerSorter}
	 * @return the index to use when inserting the element.
	 *
	 */
	private int insertionPosition(Item[] items, ViewerComparator comparator,
			int lastInsertion, Object element, TreePath parentPath) {
		int size = items.length;
		if (comparator == null) {
			return size;
		}
		int min = lastInsertion, max = size - 1;
		while (min <= max) {
			int mid = (min + max) / 2;
			Object data = items[mid].getData();
			int compare = internalCompare(comparator, parentPath, data, element);
			if (compare == 0) {
				return mid;
			}
			if (compare < 0) {
				min = mid + 1;
			} else {