/// <summary>
 /// Login.
 /// </summary>
 /// <param name='operations'>
 /// The operations group for this extension method.
 /// </param>
 /// <param name='model'>
 /// The credentials.
 /// </param>
 public static object Login(this IStsApi operations, LoginUserModel model = default(LoginUserModel))
 {
     return(operations.LoginAsync(model).GetAwaiter().GetResult());
 }