@Nullable
  public static GenericDomValue<?> getTag(DomElement domElement, @NonNls String tagName) {
    final DomFixedChildDescription fixedChildDescription = domElement.getGenericInfo().getFixedChildDescription(tagName);
    if (fixedChildDescription == null) {
      return null;
    }
    final DomElement domValueElement = ContainerUtil.getFirstItem(fixedChildDescription.getValues(domElement));
    return ObjectUtils.tryCast(domValueElement, GenericDomValue.class);
  }
@Nullable
  public static GenericDomValue<?> getTag(DomElement domElement, @NonNls String tagName)