public MessageViewModel(Message message)
 {
     _message = message;
 }
            public CorrespondenceFact CreateFact(FactMemento memento)
            {
                Message newFact = new Message(memento);

                // Create a memory stream from the memento data.
                using (MemoryStream data = new MemoryStream(memento.Data))
                {
                    using (BinaryReader output = new BinaryReader(data))
                    {
                        newFact._unique = (Guid)_fieldSerializerByType[typeof(Guid)].ReadData(output);
                        newFact._text = (string)_fieldSerializerByType[typeof(string)].ReadData(output);
                    }
                }

                return newFact;
            }