ref: a277b6aefd2a39bb7a2582ea0c6784e35c9c0a73 dir: /tests/extents/addbelow2/input/
0 1 3 1 4 1 9 1 10 1 31 1 11 1 30 1 12 1 29 1 13 1 24 1 14 1 23 1 15 1 22 1 5 1 1 1 16 1 6 1 2 1 7 1 8 1 17 1