Borders didn't shows on the TreeGrid

[treblereel]

Hi folks, looks like its a bug.

Howto reproduce:

add this to the tree :

    tree.getView().setStripeRows(true);
    tree.setBorders(false);
    tree.getView().setColumnLines(true); 

atm : nothings changed
expacted: borders like on the filtergrid

env: gxt 3.0.1 community version