https://groups.google.com/g/caelum-vraptor-dev/c/DtnWvgvSe2A
Re: PersistentBag
https://access.redhat.com/webassets/avalon/d/red_hat_jboss_enterprise_application_platform/7.3/javadocs/org/hibernate/collection/internal/PersistentBag.html
PersistentBag (Red Hat JBoss Enterprise Application Platform 7.3.0.GA public API)
red hat jboss