public IEnumerator FetchAsyncDataNotAvailable()
    {
        // テストデータ作成
        NCMBUser.LogInAsync("tarou", "tarou", (e) => {
            Assert.Null(e);

            NCMBUser.CurrentUser.SessionToken = "invalidToken";
            NCMBUser.CurrentUser._currentOperations.Clear();

            NCMBRole exampleRole = new NCMBRole("exampleRole");
            exampleRole.ObjectId = "roleInvalidObjectId";

            exampleRole.FetchAsync((NCMBException ex) =>
            {
                Assert.NotNull(ex);
                Assert.AreEqual("E404001", ex.ErrorCode);
                Assert.AreEqual("No data available.", ex.ErrorMessage);
                NCMBTestSettings.CallbackFlag = true;
            });
        });

        yield return(NCMBTestSettings.AwaitAsync());

        // 登録成功の確認
        Assert.True(NCMBTestSettings.CallbackFlag);
    }