public static TContentItem SetDate <TContentItem>(this TContentItem contentItem, string name, DateTime?value)
            where TContentItem : IContentElement
        {
            DateField field = contentItem.GetField <DateField>(name);

            field.Value = value;

            return(contentItem);
        }
        public static DateTime?GetDate(this IContentElement contentItem, string name)
        {
            DateField field = contentItem.GetField <DateField>(name);

            return(field.Value);
        }