public static MultimapBuilderWithKeys<@Nullable Object> hashKeys() {
    return hashKeys(DEFAULT_EXPECTED_KEYS);
  }

  /**
   * Uses a hash table to map keys to value collections, initialized to expect the specified number
   * of keys.
   *
   * @throws IllegalArgumentException if {@code expectedKeys < 0}
   */
  public static MultimapBuilderWithKeys<@Nullable Object> hashKeys(int expectedKeys) {

  public static MultimapBuilderWithKeys<@Nullable Object> hashKeys() {
    return hashKeys(DEFAULT_EXPECTED_KEYS);
  }

  /**
   * Uses a hash table to map keys to value collections, initialized to expect the specified number
   * of keys.
   *
   * @throws IllegalArgumentException if {@code expectedKeys < 0}
   */
  public static MultimapBuilderWithKeys<@Nullable Object> hashKeys(int expectedKeys) {

  @J2ktIncompatible
  @GwtIncompatible // doesn't build without explicit type parameters on build() methods
  public void testGenerics() {
    ListMultimap<String, Integer> unusedA = MultimapBuilder.hashKeys().arrayListValues().build();
    SortedSetMultimap<String, Integer> unusedB =
        MultimapBuilder.linkedHashKeys().treeSetValues().build();
    SetMultimap<String, Integer> unusedC =

  /**
   * Creates a new, empty {@code HashMultimap} with the default initial capacities.
   *
   * <p>You may also consider the equivalent {@code
   * MultimapBuilder.hashKeys().hashSetValues().build()}, which provides more control over the
   * underlying data structure.
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      HashMultimap<K, V> create() {

  /**
   * Creates a new, empty {@code ArrayListMultimap} with the default initial capacities.
   *
   * <p>You may also consider the equivalent {@code
   * MultimapBuilder.hashKeys().arrayListValues().build()}, which provides more control over the
   * underlying data structure.
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      ArrayListMultimap<K, V> create() {

  /**
   * Creates a new, empty {@code HashMultimap} with the default initial capacities.
   *
   * <p>You may also consider the equivalent {@code
   * MultimapBuilder.hashKeys().hashSetValues().build()}, which provides more control over the
   * underlying data structure.
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      HashMultimap<K, V> create() {

  /**
   * Creates a new, empty {@code ArrayListMultimap} with the default initial capacities.
   *
   * <p>You may also consider the equivalent {@code
   * MultimapBuilder.hashKeys().arrayListValues().build()}, which provides more control over the
   * underlying data structure.
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      ArrayListMultimap<K, V> create() {

    }
    return fromHashers(hashers);
  }

  @Override
  public Hasher newHasher(int expectedInputSize) {
    checkArgument(expectedInputSize >= 0);
    Hasher[] hashers = new Hasher[functions.length];
    for (int i = 0; i < hashers.length; i++) {
      hashers[i] = functions[i].newHasher(expectedInputSize);
    }
    return fromHashers(hashers);
  }

  private Hasher fromHashers(Hasher[] hashers) {
    return new Hasher() {

			return h.New()
		}
	}
}

// HashBorrower allows borrowing hashes and will keep track of them.
func (s *SigningMethodHMAC) HashBorrower() HashBorrower {
	return HashBorrower{pool: &s.HasherPool, borrowed: make([]hash.Hash, 0, 2)}
}

// HashBorrower keeps track of borrowed hashers and allows to return them all.
type HashBorrower struct {
	pool     *bpool.Pool[hash.Hash]
	borrowed []hash.Hash

    Random random = new Random(0);
    for (int i = 0; i < 200; i++) {
      RandomHasherAction.pickAtRandom(random).performAction(random, hashers);
    }
    HashCode[] codes = new HashCode[hashers.size()];
    for (int i = 0; i < hashers.size(); i++) {
      codes[i] = hashers.get(i).hash();
    }
    for (int i = 1; i < codes.length; i++) {
      assertEquals(codes[i - 1], codes[i]);
    }
  }