We currently only have Collections.sort whiltelisted, but every method in this class is a static utility method that is safe. Also need to whitelist a couple of Throwable.printStackTrace variations. JENKINS-57344 already whitelisted a few java.io methods to make it possible to write to a StringWriter, so together this will make it possible to log more detailed error messages that include exception stacktraces and make it easier to troubleshoot some issues.