void fillElementsToCheckDuplicates(@NotNull MultiMap<Object, PsiElement> elements, @NotNull PsiCaseLabelElement labelElement) {
    PsiExpression expr = ObjectUtils.tryCast(labelElement, PsiExpression.class);
    if (expr == null) return;
    if (expr instanceof PsiReferenceExpression ref) {
      String enumConstName = evaluateEnumConstantName(ref);
      if (enumConstName != null) {
        elements.putValue(enumConstName, labelElement);
        return;
      }
    }
    Object value = ConstantExpressionUtil.computeCastTo(expr, mySelectorType);
    if (value != null) {
      elements.putValue(value, expr);
    }
  }
void fillElementsToCheckDuplicates(@NotNull MultiMap<Object, PsiElement> elements, @NotNull PsiCaseLabelElement labelElement)