Bug 111631 [Viewers] TreeViewer needs more TableViewer API
As the TreeViewer is meant to replace the TableTreeViewer we need to add some of the API that the TableViewer had to it so that it can be used like a table. public void insert(Object element, int position) public void add(Object[] objects) Both need to be added.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* Sets the expand state of the given item.
     * 
     * @param item
     *           the item
     * @param expand
     *           the expand state of the item
     */
    protected abstract void setExpanded(Item item, boolean expand);
    /**
     * Sets which nodes are expanded in this viewer's tree. The given list
     * contains the elements that are to be expanded; all other nodes are to be
     * collapsed.
     * <p>
     * This method is typically used when restoring the interesting state of a
     * viewer captured by an earlier call to <code>getExpandedElements</code>.
     * </p>
     * 
     * @param elements
     *           the array of expanded elements
     * @see #getExpandedElements
     */
    public void setExpandedElements(Object[] elements) {
        assertElementsNotNull(elements);
        CustomHashtable expandedElements = newHashtable(elements.length * 2 + 1);
        for (int i = 0; i < elements.length; ++i) {
            Object element = elements[i];