private @NotNull Map<K, V> toMapInner() {
    Map<K, V> map = new HashMap<>(size());
    for (int i = 0; i < myData.length; i += 2) {
      map.put(asKey(i), asValue(i + 1));
    }
    return map;
  }
private @NotNull Map<K, V> toMapInner()