public static @Nullable LanguageLevel getNextLanguageLevel(@NotNull LanguageLevel api) {
    final LanguageLevel[] levels = LanguageLevel.values();
    final int currentLevelId = api.ordinal();
    for (int i = currentLevelId + 1; i < levels.length; i++) {
      final LanguageLevel level = levels[i];
      if (!level.isPreview()) return level;
    }
    return null;
  }
public static @Nullable LanguageLevel getNextLanguageLevel(@NotNull LanguageLevel api)