There is an undocumented [shieldId attribute in the returned studyInfo object](https://github.com/mozilla/shield-studies-addon-utils/blob/master/webExtensionApis/study/src/studyUtils.js#L413-L437). Seems to be a remnant from v4 or earlier. Is it relevant for modern shield studies? Document it or remove it?
There is an undocumented shieldId attribute in the returned studyInfo object. Seems to be a remnant from v4 or earlier. Is it relevant for modern shield studies? Document it or remove it?