I feel that the addAll method of BeacnContainer should be
addAll(Iterable<? extends BEANTYPE> beans)
instead of
addAll(Collection<? extends BEANTYPE> beans)
Now after Vaadin 7 is out, it is problematic to make such API changes, but please
create an enhancement request
for the future.
http://dev.vaadin.com/ticket/11130
Yea, I know I should have seen it during the beta phase.