*/
  public static <E extends @Nullable Object> CompactHashSet<E> create(
      Collection<? extends E> collection) {
    CompactHashSet<E> set = createWithExpectedSize(collection.size());
    set.addAll(collection);
    return set;
  }

  /**
   * Creates a <i>mutable</i> {@code CompactHashSet} instance containing the given elements in
   * unspecified order.
   *

   *     elements without resizing
   * @throws IllegalArgumentException if {@code expectedSize} is negative
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      CompactHashMap<K, V> createWithExpectedSize(int expectedSize) {
    return new CompactHashMap<>(expectedSize);
  }

  private static final Object NOT_FOUND = new Object();

  /**

   *     elements without resizing
   * @throws IllegalArgumentException if {@code expectedSize} is negative
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      CompactHashMap<K, V> createWithExpectedSize(int expectedSize) {
    return new CompactHashMap<>(expectedSize);
  }

  private static final Object NOT_FOUND = new Object();

  /**