public Task LoginAsync(string username, string password, CancellationToken ct = default(CancellationToken))
        {
            user = new User()
            {
                Username = username,
                Password = password
            };

            return _bootcampService.PostAsync("Users/Login", user, ct);
        }
 public async Task LogoutAsync(CancellationToken ct = default(CancellationToken))
 {
     await Task.Delay(1000, ct);
     user = null;
 }