using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(string.Format(

            "Currently logged in user with token {0}, user is {1} years old",

            UserInfo.Instance.UserToken, (DateTime.Now - UserInfo.Instance.DateOfBirth).Days / 365));

    }

}

​

public sealed class UserInfo

{

    private static readonly UserInfo _instance;

    private UserInfo() {}

    static UserInfo()

    {

        _instance = new UserInfo();

        _instance.DateOfBirth = new DateTime(1986, 3, 20);

        _instance.UserToken = Guid.Parse("c1a62826-b1e9-4bec-9607-9dc1dbbac1d1");

    }

    public static UserInfo Instance

    {

        get { return _instance; }

    }

    public Guid UserToken {get;set;}

    public DateTime DateOfBirth {get;set;}

}