Opened "tattrreg.h5" with sec2 driver.
Dataset1                 Dataset {NULL}
    Attribute: Attribute1 {4}
        Type:      dataset region reference
        Data:  DSET-/Dataset2 {Blk0: (2,2)-(7,7)}, DSET-/Dataset2 {Pt0: (6,9),
                 Pt1: (2,2), Pt2: (8,4), Pt3: (1,6), Pt4: (2,8), Pt5: (3,2),
                 Pt6: (0,4), Pt7: (9,0), Pt8: (7,1), Pt9: (3,3)}, NULL, NULL
    Location:  1:1400
    Links:     1
    Storage:   0 logical bytes, 0 allocated bytes
    Type:      native int
    Data:

Dataset2                 Dataset {10/10, 10/10}
    Location:  1:800
    Links:     1
    Storage:   100 logical bytes, 100 allocated bytes, 100.00% utilization
    Type:      8-bit unsigned integer
    Data:
        (0,0) 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48,
        (1,7) 51, 54, 57, 60, 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 96,
        (3,3) 99, 102, 105, 108, 111, 114, 117, 120, 123, 126, 129, 132, 135,
        (4,6) 138, 141, 144, 147, 150, 153, 156, 159, 162, 165, 168, 171, 174,
        (5,9) 177, 180, 183, 186, 189, 192, 195, 198, 201, 204, 207, 210, 213,
        (7,2) 216, 219, 222, 225, 228, 231, 234, 237, 240, 243, 246, 249, 252,
        (8,5) 255, 2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35, 38, 41