static Map mapKeyAndFunction(Iterable l, O f) {
  ret mapKeyAndFunction(f, l);
}

static Map mapLike mapKeyAndFunction(O f, Iterable l) {
  new HashMap map;
  if (l != null) for (O o : l)
    map.put(o, callF(f, o));
  ret map;
}

static <A, B, C> Map<A, C> mapKeyAndFunction(Map<A, B> map, IF2<A, B, C> f) {
  new HashMap map2;
  if (map != null) for (A key, B value : map)
    map2.put(key, callF(f, key, value));
  ret map2;
}


static <A, B> Map<A, B> mapKeyAndFunction(Iterable<A> l, IF1<A, B> f) {
  ret mapKeyAndFunction(f, l);
}

Began life as a copy of #1018013