Bug 33040 No single Undo for generate delegate methods
RC 1 - JUnit setup - open TestCase - select fName - generate delegate methods for all String methods - press Ctrl+Z Observe: only one method is removed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/AddDelegateMethodsAction.java
}
			MessageDialog.openInformation(getShell(), DIALOG_TITLE, ActionMessages.getString("AddDelegateMethodsAction.not_applicable")); 
		} catch (CoreException e) {
			ExceptionHandler.handle(e, getShell(), DIALOG_TITLE, ActionMessages.getString("AddDelegateMethodsAction.error.actionfailed")); 
		}
	}
	
	
	private void showUI(IType type, IField[] preselected) {
		try {
			FieldContentProvider provider = new FieldContentProvider(type);
			Methods2FieldLabelProvider methodLabel = new Methods2FieldLabelProvider();
			CheckedTreeSelectionDialog dialog = new CheckedTreeSelectionDialog(getShell(), methodLabel, provider);
			dialog.setValidator(new ISelectionStatusValidator() {
				public IStatus validate(Object[] selection) {
					StatusInfo state = new StatusInfo();
					if (selection != null && selection.length > 0) {
						HashSet map = new HashSet(selection.length);
						int count = 0;
						for (int i = 0; i < selection.length; i++) {
							Object key = selection[i];
							if (selection[i] instanceof Methods2Field) {
								count++;
								try {
									key = createSignatureKey(((Methods2Field) selection[i]).fMethod);
								} catch (JavaModelException e) {
									return new StatusInfo(StatusInfo.ERROR, e.toString());
								}
							}
							if (!map.add(key)) {