Bug 153993 [Viewers] Common Baseclass for Tree/TableEditorImpl
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TableTreeViewer.java
*/
    protected int getItemCount(Item item) {
        return ((TableTreeItem) item).getItemCount();
    }
    /* (non-Javadoc)
     * Method declared on AbstractTreeViewer.
     */
    protected org.eclipse.swt.widgets.Item[] getItems(
            org.eclipse.swt.widgets.Item item) {
        return ((TableTreeItem) item).getItems();
    }
    /**
     * The table tree viewer implementation of this <code>Viewer</code> framework
     * method returns the label provider, which in the case of table tree
     * viewers will be an instance of either <code>ITableLabelProvider</code>
     * or <code>ILabelProvider</code>.
     * If it is an <code>ITableLabelProvider</code>, then it provides a
     * separate label text and image for each column. If it is an 
     * <code>ILabelProvider</code>, then it provides only the label text 
     * and image for the first column, and any remaining columns are blank.
     */
    public IBaseLabelProvider getLabelProvider() {
        return super.getLabelProvider();
    }
    /* (non-Javadoc)
     * Method declared on AbstractTreeViewer.
     */
    protected Item getParentItem(Item item) {
        return ((TableTreeItem) item).getParentItem();
    }