static <A, B> bool syncMapRemoveKeyAndValuePair(Map<A, B> map, A key, B value) {
  if (map == null || key == null || value == null) false;
  synchronized(collectionMutex(map)) {
    B actualValue = map.get(key);
    if (eq(actualValue, value)) {
      map.remove(key);
      true;
    }
    false;
  }
}

Began life as a copy of #1030838