private void Save(DataWriter textWriter)
        {
            textWriter.WriteStringWithLength(UserId);

            textWriter.WriteInt32(DiscoveryInfoForServices.Count);

            foreach (var i in DiscoveryInfoForServices)
            {
                textWriter.WriteStringWithLength(i.Key);
                textWriter.WriteStringWithLength(i.Value.ServiceResourceId);
                textWriter.WriteStringWithLength(i.Value.ServiceEndpointUri.ToString());
                textWriter.WriteStringWithLength(i.Value.ServiceApiVersion);
            }
        }