GWT - TreeTable?

I'm looking for a way to extend GWT FlexTable or CellTable to a "TreeTable". I want a table with expandable rows, and I want to be able to get the data from the sever when it's needed. So I don't want to populate the whole table (all levels) from the start.

Is it best to use a FlexTable or a CellTable to start with? Or are there any examples/plugins on the web for this?

All idea开发者_如何学Pythons and tips are appreciated!

I found a TreeTable widget at Google Web Toolkit Incubator . Here is the demo