@Test
public void shouldThrowExeptionWhileMovingDownWithoutChilds() {

    KeePassFile keePassFile = createFlatGroupStructure();
    GroupZipper zipper = new GroupZipper(keePassFile).down();
    expectedException.expect(RuntimeException.class);
    expectedException.expectMessage("Could not move down because this group does not have any children");
    zipper.down();
}