private static bool FromGuidToString(Guid guid, CastingContext context, string defaultStr, out object result)
 {
     result = StringConv.GuidToString(guid, context, defaultStr);
     return(true);
 }
 private static bool FromNullableGuidToString(Guid?guid, CastingContext context, out object result)
 {
     result = StringConv.GuidToString(guid, context);
     return(true);
 }