The complete DDS:
Dataset {
    Int32 i[20];
    Int32 j;
    String s;
    Grid {
      Array:
        Float64 val[length = 5][width = 6][height = 7];
      Maps:
        Float64 length[5];
        Float64 width[6];
        Float64 height[7];
    } g;
} test1;
The data:
Structure {
    Float64 val[length = 2][width = 2][height = 2];
} g = { {{{99.999, 99.999},{99.999, 99.999}},{{99.999, 99.999},{99.999, 99.999}}} };