Editable textfield in TreeConfig

Hi.

I have created wizard having tree as a step. Tree has WTDocuments as root nodes and WTParts as second level nodes.

I need to add editable field in wtPart row to specify number of parts.

I cann't find any examples in customization guide but only few words "you can write a wrapper class extending from NmObject  and override getOid() method to return proper NmOid."

A created wrapper for my tree nodes, but all i see now is empty tree.

Can anyone give me sample code for same problem?

I have used AbstractComponentBuilder as ComponentBuilder for my tree and TreeHandlerAdapter to provide data.

Thanks.