static <A, B> void lambdaMapLike putIfHigherByCalculatedField(IF1<B, ? extends Comparable> scorer, Map<A, B> map, A key, B value) {
  if (map == null || key == null || value == null) ret;
  B existing = map.get(key);
  if (existing == null || cmp(scorer.get(value), scorer.get(existing)) > 0)
    map.put(key, value);
}

Began life as a copy of #1008400