Findbugs says that naming a class the same name as one of the classes it is implementing leads to confusion, having to check imports, etc.
org.switchyard.security.principal.Group implements java.security.acl.Group which could cause significant confusion. Investigate whether we can change the class name, whether there are API impact to changing the class name.
There is an exception for this logged in find bugs in core/src/main/resources/findbugs/findbugs-excludes.xml (see JIRA # reference). If fixing this issue, please remove the excludes exception as well in the commit.