String hash = "01010101010101010101010101010101";
        String value = "$H4sIAAAAAAAA_zMwNMALAXC7sg0gAAAA";
        assertEquals(value, documentHelper.encodeSimilarDocHash(hash));
        hash = "00101010010010100100101010001010";
        value = "$H4sIAAAAAAAA_zMwMARDCELQQApMAgAi5-3LIAAAAA";
        assertEquals(value, documentHelper.encodeSimilarDocHash(hash));

      key[i] = (byte) i;
      int seed = 256 - i;
      byte[] hash = hashFunction.hash(Arrays.copyOf(key, i), seed);
      System.arraycopy(hash, 0, hashes, i * hashBytes, hash.length);
    }

    // Then hash the result array
    byte[] result = hashFunction.hash(hashes, 0);

    // interpreted in little-endian order.
    int verification = Integer.reverseBytes(Ints.fromByteArray(result));

    if (expected != verification) {

   * input.
   */
  @VisibleForTesting(
      )
  static final double HASH_FLOODING_FPP = 0.001;

  /**
   * Maximum allowed length of a hash table bucket before falling back to a j.u.LinkedHashSet based
   * implementation. Experimentally determined.
   */
  private static final int MAX_HASH_BUCKET_LENGTH = 9;

   * input.
   */
  @VisibleForTesting(
      )
  static final double HASH_FLOODING_FPP = 0.001;

  /**
   * Maximum allowed length of a hash table bucket before falling back to a j.u.LinkedHashMap-based
   * implementation. Experimentally determined.
   */
  private static final int MAX_HASH_BUCKET_LENGTH = 9;

   *       y}, if {@code equivalent(x, y)}, then {@code hash(x) == hash(y)}. It is <i>not</i>
   *       necessary that the hash be distributable across <i>inequivalence</i>. If {@code
   *       equivalence(x, y)} is false, {@code hash(x) == hash(y)} may still be true.
   *   <li>{@code hash(null)} is {@code 0}.
   * </ul>
   */
  public final int hash(@CheckForNull T t) {
    if (t == null) {
      return 0;
    }

   *       y}, if {@code equivalent(x, y)}, then {@code hash(x) == hash(y)}. It is <i>not</i>
   *       necessary that the hash be distributable across <i>inequivalence</i>. If {@code
   *       equivalence(x, y)} is false, {@code hash(x) == hash(y)} may still be true.
   *   <li>{@code hash(null)} is {@code 0}.
   * </ul>
   */
  public final int hash(@CheckForNull T t) {
    if (t == null) {
      return 0;
    }

      HashFunction func = cell.getRowKey();
      String input = cell.getColumnKey();
      String expected = cell.getValue();
      assertEquals(
          String.format(Locale.ROOT, "Known hash for hash(%s, UTF_8) failed", input),
          expected,
          func.hashString(input, UTF_8).toString());
    }
  }

  public void testNullPointers() {
    NullPointerTester tester =

   */

  private MultimapBuilder() {}

  private static final int DEFAULT_EXPECTED_KEYS = 8;

  /** Uses a hash table to map keys to value collections. */
  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.
   *

  // We can include the non-BMP fix here because Hashing.goodFastHash stresses that the hash is a
  // temporary-use one. Therefore it shouldn't be persisted.
  static final HashFunction GOOD_FAST_HASH_32 =
      new Murmur3_32HashFunction(Hashing.GOOD_FAST_HASH_SEED, /* supplementaryPlaneFix= */ true);

  private static final int CHUNK_SIZE = 4;

  private static final int C1 = 0xcc9e2d51;

 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash
 * function doing a good job of distributing the elements to the buckets to a distribution not far
 * from uniform), and amortized since some operations can trigger a hash table resize.
 *
 * <p>As compared with {@link java.util.LinkedHashMap}, this structure places significantly reduced