public override XmlString Format(List <double> list)
        {
            StringBuilder sb = new StringBuilder(list.Count * 3);

            foreach (var d in list)
            {
                sb.Append(Double2XmlSerializer.FormatG17(d)).Append(';');
            }
            return(new XmlString(sb.ToString()));
        }
 protected override string FormatValue(object o)
 {
     return(Double2XmlSerializer.FormatG17((double)o));
 }