assertArrayEquals(new int[] { 5, 6 }, merged.get(1));
assertArrayEquals(new int[] { 12, 8 }, merged.get(2));
assertArrayEquals(new int[] { 8, 7 }, merged.get(3));
assertArrayEquals(new int[] { 5, 6 }, merged.get(1));
assertArrayEquals(new int[] { 12, 8 }, merged.get(2));
assertArrayEquals(new int[] { 8, 7 }, merged.get(3));