docs: private static boolean ensureAtMostOneDeclaredDefault(Map.Entry<String, List<BuiltInQProfile.Builder>> entry) {
      Set<String> declaredDefaultProfileNames = entry.getValue().stream()
        .filter(BuiltInQProfile.Builder::isDeclaredDefault)
        .map(BuiltInQProfile.Builder::getName)
        .collect(MoreCollectors.toSet());
      checkState(declaredDefaultProfileNames.size() <= 1, "Several Quality profiles are flagged as default for the language %s: %s", entry.getKey(), declaredDefaultProfileNames);
      return true;
    }