rank=2 dims=(8,8) chunks=(3,3)
[0/0][0/0] = 00 01 02 | 08 09 10 | 16 17 18
[0/0][1/3] = 03 04 05 | 11 12 13 | 19 20 21
[0/0][2/6] = 06 07 -1 | 14 15 -1 | 22 23 -1
[1/3][0/0] = 24 25 26 | 32 33 34 | 40 41 42
[1/3][1/3] = 27 28 29 | 35 36 37 | 43 44 45
[1/3][2/6] = 30 31 -1 | 38 39 -1 | 46 47 -1
[2/6][0/0] = 48 49 50 | 56 57 58 | -1 -1 -1
[2/6][1/3] = 51 52 53 | 59 60 61 | -1 -1 -1
[2/6][2/6] = 54 55 -1 | 62 63 -1 | -1 -1 -1