Bug 153993 [Viewers] Common Baseclass for Tree/TableEditorImpl
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TableTreeViewer.java
return ((TableTree) widget).getItem (index);
	}
      return null;
    }
    /**
     * Returns the column properties of this viewer.
     * The properties must correspond with the columns of the table control.
     * They are used to identify the column in a cell modifier.
     *
     * @return the list of column properties
     */
    public Object[] getColumnProperties() {
        return tableViewerImpl.getColumnProperties();
    }
    /* (non-Javadoc)
     * Method declared on Viewer.
     */
    public Control getControl() {
        return tableTree;
    }
    /**
     * Returns the element with the given index from this viewer.
     * Returns <code>null</code> if the index is out of range.
     * <p>
     * This method is internal to the framework.
     * </p>
     *
     * @param index the zero-based index
     * @return the element at the given index, or <code>null</code> if the
     *   index is out of range