(static) PersistableObject Construct()
      (ctor) ItemValue()
      (ctor) ItemValue( string value )
      (ctor) ItemValue( string value, string format )
      string Format( get; set; )
      PersistableType TypeID( get; )
      string Value( get; set; )
      virtual void DeserializeAttributes( PersistanceReader ip )
      virtual void SerializeAttributes( PersistanceWriter op )