Deserialize ExtensionData

public class DirectoryAccount
{
    // normal deserialization
    public string DisplayName { get; set; }

    // these properties are set in OnDeserialized
    public string UserName { get; set; }
    public string Domain { get; set; }

    [JsonExtensionData]
    private IDictionary<string, JToken> _additionalData;

    [OnDeserialized]
    private void OnDeserialized(StreamingContext context)
    {
        // SAMAccountName is not deserialized to any property
        // and so it is added to the extension data dictionary
        string samAccountName = (string)_additionalData["SAMAccountName"];

        Domain = samAccountName.Split('\\')[0];
        UserName = samAccountName.Split('\\')[1];
    }

    public DirectoryAccount()
    {
        _additionalData = new Dictionary<string, JToken>();
    }
}

string json = @"{
  'DisplayName': 'John Smith',
  'SAMAccountName': 'contoso\\johns'
}";

DirectoryAccount account = JsonConvert.DeserializeObject<DirectoryAccount>(json);

Console.WriteLine(account.DisplayName);
// John Smith

Console.WriteLine(account.Domain);
// contoso

Console.WriteLine(account.UserName);
// johns