public static TContentItem SetReference <TContentItem>(this TContentItem contentItem, string name, ContentItem?reference)
            where TContentItem : IContentElement
        {
            ReferenceField field = contentItem.GetField <ReferenceField>(name);

            field.ContentItem = reference;

            return(contentItem);
        }
        public static ContentItem?GetReference(this IContentElement contentItem, string name)
        {
            ReferenceField field = contentItem.GetField <ReferenceField>(name);

            return(field.ContentItem);
        }