Bug 127861 [DataBinding] Mark API provisional
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/viewers/TreeViewerDescription.java
/**
	 * Table column may spedify a nested property
	 */
	public static final String COLUMN_PROPERTY_NESTING_SEPERATOR = "."; 
	private TreeViewer treeViewer;
	
	private HashMap columnsMap = new HashMap();  
	
	private ICellModifier cellModifier = null;
	/**
	 * @param treeViewer
	 */
	public TreeViewerDescription(TreeViewer treeViewer) {
		this.treeViewer = treeViewer;
	}
	/**
	 * @param instanceType 
	 * @param columnIndex
	 * @param propertyName
	 * @param cellEditor 
	 * @param validator
	 * @param converter
	 *            converter from model objects to String, or ImageAndString.
	 */
	public void addColumn(Class instanceType, int columnIndex, String propertyName,
			CellEditor cellEditor, IValidator validator, IConverter converter) {
		List columns = (List)columnsMap.get(instanceType);
		if (columns==null) {