public Task TestLogOut() {
      var controller = new ParseCurrentUserController();
      var user = new ParseUser();

      return controller.SetAsync(user, CancellationToken.None).OnSuccess(_ => {
        Assert.AreEqual(user, controller.CurrentUser);
        return controller.ExistsAsync(CancellationToken.None);
      }).Unwrap()
      .OnSuccess(t => {
        Assert.IsTrue(t.Result);

        return controller.LogOutAsync(CancellationToken.None);
      }).Unwrap().OnSuccess(_ => controller.GetAsync(CancellationToken.None)).Unwrap()
      .OnSuccess(t => {
        Assert.IsNull(t.Result);

        return controller.ExistsAsync(CancellationToken.None);
      }).Unwrap()
      .OnSuccess(t => {
        Assert.IsFalse(t.Result);
      });
    }