@NotNull
  public static LanguageLevel getEffectiveLanguageLevel(@NotNull final Module module) {
    ApplicationManager.getApplication().assertReadAccessAllowed();
    LanguageLevel level = getCustomLanguageLevel(module);
    if (level != null) return level;
    return LanguageLevelProjectExtension.getInstance(module.getProject()).getLanguageLevel();
  }
@NotNull
  public static LanguageLevel getEffectiveLanguageLevel(@NotNull final Module module)