// TODO: this approach can work for full hierarchy?;
// TaxoReader can't do this since ords are not in
// "sorted order" ... but we should generalize this to
// support arbitrary hierarchy:
for(int ord=0;ord<valueCount;ord++) {
dv.lookupOrd(ord, spare);
String[] components = spare.utf8ToString().split(separatorRegex, 2);
if (components.length != 2) {
throw new IllegalArgumentException("this class can only handle 2 level hierarchy (dim/value); got: " + spare.utf8ToString());
}
if (!components[0].equals(lastDim)) {