@Contract(pure = true)
  public static @NotNull <K, V> Map<K, V> map2Map(@NotNull Collection<? extends Pair<? extends K, ? extends V>> collection) {
    Map<K, V> result = new HashMap<>(collection.size());
    for (Pair<? extends K, ? extends V> pair : collection) {
      result.put(pair.first, pair.second);
    }
    return result;
  }
@Contract(pure = true)
  public static @NotNull <K, V> Map<K, V> map2Map(@NotNull Collection<? extends Pair<? extends K, ? extends V>> collection)