public int compare(Object o1, Object o2) {
final Document d1 = (Document) o1;
final Document d2 = (Document) o2;
try {
return compareDocuments(d1, d2);
} catch (NullPointerException npe) {
NullPointerException nullPointerException =
new NullPointerException(
"Tried sorting on null fields! You need to call .nullsFirst() or .nullsLast() on your Comparator.");
nullPointerException.initCause(npe);
throw nullPointerException;
}
}