docs: protected RoleGroup extract(Subject subject) {
          Optional<Principal> match = subject.getPrincipals()
                  .stream()
                  .filter(g -> g.getName().equals(SecurityConstants.ROLES_IDENTIFIER))
                  .findFirst();
          Group rolesGroup = (Group) match.get();
          RoleGroup roles = new SimpleRoleGroup(rolesGroup);
          return roles;
      }