+ Iterator<CmsSessionId> it = subject.getPrivateCredentials(CmsSessionId.class).iterator();
+ if (!it.hasNext())
+ throw new IllegalStateException("No CMS session id available for " + subject);
+ CmsSessionId cmsSessionId = it.next();
+ if (it.hasNext())
+ throw new IllegalStateException("More than one CMS session id available for " + subject);