@Contract("null -> null")
  @Nullable
  public static PsiExpression getSwitchSelectorExpression(PsiExpression expression) {
    if (expression == null) return null;
    final LanguageLevel languageLevel = PsiUtil.getLanguageLevel(expression);
    final PsiExpression selectorExpression = getPossibleSwitchSelectorExpression(expression, languageLevel);
    return canBeSwitchSelectorExpression(selectorExpression, languageLevel) ? selectorExpression : null;
  }
@Contract("null -> null")
  @Nullable
  public static PsiExpression getSwitchSelectorExpression(PsiExpression expression)