public List<BackgroundDataWithIndex> getBackgroundDataWithIndex() {
        return toScesimDataWithIndex(BackgroundDataWithIndex::new);
    }
@Test
    public void getBackgroundDataWithIndex() {
        List<BackgroundDataWithIndex> backgroundDatas = background.getBackgroundDataWithIndex();
        
        assertThat(backgroundDatas).hasSameSizeAs(background.getUnmodifiableData());
        BackgroundDataWithIndex backgroundData = backgroundDatas.get(0);
        int index = backgroundData.getIndex();
        assertThat(backgroundData.getScesimData()).isEqualTo(background.getDataByIndex(index - 1));
    }