static <A, B> Map<A, B> lambdaMapLike filterByValuePredicate(IPred<B> pred, Map<A, B> map) {
  if (map == null) null;
  Map<A, B> map2 = similarEmptyMap(map);
  for (Map.Entry<A, B> e : map.entrySet())
    if (pred.get(e.getValue()))
      map2.put(e.getKey(), e.getValue());
  ret map2;
}

static <A, B> Map<A, B> filterByValuePredicate(Map<A, B> map, IPred<B> pred) {
  ret filterByValuePredicate(pred, map);
}

Began life as a copy of #1028141