为什么我的用户不是使用图形API在Azure AD中创建的？

Question

我使用以下代码创建一个虚拟用户：

public void AddDummyUser(string email)
{
    var user = new User
    {
        AccountEnabled = true,
        DisplayName = "Dummy User",
        UserPrincipalName = email, // email = "DummyUser@xx.onmicrosoft.com"
        PasswordProfile = new PasswordProfile
        {
            ForceChangePasswordNextLogin = false,
            Password = "Demo2016!"
        },
        MailNickname = "DummyUser",
        GivenName = "Dummy",
        Surname = "User",
        JobTitle = "n.v.t.",
        Department = "n.v.t.",
        City = "n.v.t.",
        State = "n.v.t.",
        Mobile = "n.v.t.",
        UsageLocation = "US"
    };
    var adClient = GetAdClient();
    adClient.Users.AddUserAsync(user); // When I use .Wait() the application hangs and nothing happens.
}

我知道我可以连接到我的Azure AD，因为我可以通过它的电子邮件检索用户。以下代码工作得很好：

 private User GetUserByEmail(string email)
{
    /*
        OtherMails is the "ALTERNATE EMAIL ADDRESS" in Azure AD.
        Source: http://stackoverflow.com/a/35782771/40676
        */
    var adClient = GetAdClient();
    var userLookupTask = adClient.Users
            .Where(u => u.OtherMails.Any(m => m.Equals(email, StringComparison.OrdinalIgnoreCase)))
            .ExecuteAsync()
            .Result
            .CurrentPage
            .FirstOrDefault();

    User user = (User)userLookupTask;
    return user;
}

两种方法属于同一类。

我在这里做错了什么？

编辑：

当我第一次调用GetUserByEmail然后调用AddDummyUser时，我看到正在Azure AD中创建用户。对此非常非常困惑......