@NotNull
  public static List<PsiEnumConstant> findEnumConstants(PsiSwitchLabelStatementBase label) {
    if (label == null) {
      return Collections.emptyList();
    }
    final PsiCaseLabelElementList list = label.getCaseLabelElementList();
    if (list == null) {
      return Collections.emptyList();
    }
    List<PsiEnumConstant> constants = new ArrayList<>();
    for (PsiCaseLabelElement labelElement : list.getElements()) {
      if (labelElement instanceof PsiDefaultCaseLabelElement ||
          labelElement instanceof PsiExpression expr && ExpressionUtils.isNullLiteral(expr)) {
        continue;
      }
      if (labelElement instanceof PsiReferenceExpression) {
        final PsiElement target = ((PsiReferenceExpression)labelElement).resolve();
        if (target instanceof PsiEnumConstant) {
          constants.add((PsiEnumConstant)target);
          continue;
        }
      }
      return Collections.emptyList();
    }
    return constants;
  }
@NotNull
  public static List<PsiEnumConstant> findEnumConstants(PsiSwitchLabelStatementBase label)