void DoAddExistingElementTest(string testName)
        {
            try
            {
                ITesteableApplicationWindow window =
                    GuiTesteableServices.GetApplicationWindow();

                window.ChangeText("Hello");
                window.ClickAddButton();

                WaitingAssert.AreEqual(
                    "Adding element Hello...",
                    window.GetProgressMessage,
                    "The progress message does not match the expected one " +
                    "while adding 'Hello'.");

                WaitingAssert.IsTrue(
                    window.AreButtonsEnabled,
                    "The window buttons were not re-enabled in a reasonable time.");

                Assert.IsEmpty(
                    window.GetText(),
                    "The window's text should be empty after the buttons are re-enabled.");

                window.ChangeText("Hello");
                window.ClickAddButton();

                WaitingAssert.AreEqual(
                    "Adding element Hello...",
                    window.GetProgressMessage,
                    "The progress message does not match the expected one " +
                    "while adding 'Hello'.");

                // We don't know at which point the background operation will
                // end and the error message will show up, so we'll have to
                // wait for the error message to be different than null.
                WaitingAssert.IsNotNull(
                    window.GetErrorDialog,
                    "The error message did not show up in a reasonable time.");

                ITesteableErrorDialog dialog = window.GetErrorDialog();

                Assert.AreEqual(
                    "Error", dialog.GetTitle(),
                    "The error dialog's title does not match the expected one.");

                Assert.AreEqual(
                    "The element Hello is already in the list, and thus it can't be added!",
                    dialog.GetMessage(),
                    "The error dialog's text does not match the expected one.");

                dialog.ClickOkButton();
            }
            catch (Exception ex)
            {
                mLog.Error(ex.Message);
                mLog.Error(ex.StackTrace);
            }
        }
        void DoRemoveUnexistingElementTest(string testName)
        {
            try
            {
                ITesteableApplicationWindow window =
                    GuiTesteableServices.GetApplicationWindow();

                window.ChangeText("Hello");
                window.ClickRemoveButton();

                WaitingAssert.AreEqual(
                    "Removing element Hello...",
                    window.GetProgressMessage,
                    "The progress message did not match the expected one " +
                    "while removing 'Hello'.");

                WaitingAssert.IsNotNull(
                    window.GetErrorDialog,
                    "The error message did not show up in a reasonable time.");

                ITesteableErrorDialog dialog = window.GetErrorDialog();

                Assert.AreEqual(
                    "Error", dialog.GetTitle(),
                    "The error dialog's title does not match the expected one.");

                Assert.AreEqual(
                    "The element Hello is not in the list, and thus it can't be removed!",
                    dialog.GetMessage(),
                    "The error dialog's text does not match the expected one.");

                dialog.ClickOkButton();
            }
            catch (Exception ex)
            {
                mLog.Error(ex.Message);
                mLog.Error(ex.StackTrace);
            }
        }