    @Test
    public void lastCalibrationAlert() {

        // :: Setup
        UserNotification.create("test1", "calibration_alert", System.currentTimeMillis());
        UserNotification.create("test2", "calibration_alert", System.currentTimeMillis());

        // :: Act
        UserNotification userNotification = UserNotification.lastCalibrationAlert();

        // :: Verify
        assertThat(userNotification.calibration_alert).isTrue();
        assertThat(userNotification.message).isEqualTo("test2");
    }