How to add checkboxes in table column?

Hi.

I need to add columns with checkboxes for my wizard.

Wizard tree:

tree.setRowBasedObjectHandle(true);

ColumnConfig in ComponentBuilder:

ColumnConfig paperConfig = factory.newColumnConfig("columnId", false);

paperConfig.setComponentMode(ComponentMode.EDIT);

paperConfig.setDataUtilityId("myCheckboxDataUtility");

tree.addComponent(paperConfig);

GuiComponent in DataUtility:

AttributeGuiComponent guiComponent = new BooleanInputComponent();

((BooleanInputComponent) guiComponent).setStyle(BooleanInputComponent.Style.CHECKBOX);

Then i try to get data in FormProcessor, but ObjectBean.getChecked() method returns map with null key and null element in the list only.

Can anyone say where is an error or offer another solution?

Thanks.