l0rdn1kk0n/wicket-bootstrap — pull request #146 by heapifyman (2013-03-03 03:21:56+00:00)
Title: add dropdown-submenu (#144)

I tried to implement sub menu for DropDownButton.
There's a probably very bad hack in AssertValidButtonPredicate to avoid adding a ButtonBehavior to the DropDownSubMenu. Otherwise the ButtonBehavior's Components.assertTag would fail.
I wasn't sure how to circumvent this in another way.