static <A, B> B syncGetOrCreate(Map<A, B> map, A key, Class<? extends B> c) ctex {
  synchronized(map) { ret getOrCreate(map, key, c); }
}

// f : func -> B
static <A, B> B syncGetOrCreate(Map<A, B> map, A key, O f) {
  synchronized(map) { ret getOrCreate(map, key, f); }
}


static <A, B> B nuLike syncGetOrCreate(Class<? extends B> c, Map<A, B> map, A key) {
  ret syncGetOrCreate(map, key, c);
}


static <A, B> B syncGetOrCreate(Map<A, B> map, A key, IF0<B> f) {
  synchronized(map) { ret getOrCreate(map, key, f); }
}

Began life as a copy of #1013935