private static void validate(GroupIndex index, AISValidationOutput output) {
int bitsNeeded = index.leafMostTable().getDepth() - index.rootMostTable().getDepth() + 1;
assert bitsNeeded > 0 : index;
if (bitsNeeded > Long.SIZE) {
output.reportFailure(new AISValidationFailure(new GroupIndexDepthException(index, bitsNeeded)));
}
}