@Test
void shouldThrowExceptionIfUserNameIsEmpty() {

    UserProfileContext context = new UserProfileContext(mockGazePlay);
    FlowPane choicePanel = new FlowPane();
    ImagePattern imagePattern = new ImagePattern(new Image("bear.jpg"));
    assertThrows(IllegalArgumentException.class,
        () -> context.createUser(mockGazePlay, choicePanel, "", imagePattern, false, false, screenDimension));
}