assertEquals(0x1111111111111111L, HashCode.fromLong(0x1111111111111111L).padToLong());
    assertEquals(0x9999999999999999L, HashCode.fromLong(0x9999999999999999L).padToLong());
    assertEquals(0x0000000011111111L, HashCode.fromInt(0x11111111).padToLong());
    assertEquals(0x0000000099999999L, HashCode.fromInt(0x99999999).padToLong());
  }

  public void testPadToLongWith4Bytes() {

    assertEquals(0x1111111111111111L, HashCode.fromLong(0x1111111111111111L).padToLong());
    assertEquals(0x9999999999999999L, HashCode.fromLong(0x9999999999999999L).padToLong());
    assertEquals(0x0000000011111111L, HashCode.fromInt(0x11111111).padToLong());
    assertEquals(0x0000000099999999L, HashCode.fromInt(0x99999999).padToLong());
  }

  public void testPadToLongWith4Bytes() {

   * value with {@code asBytes()} as the least-significant bytes and {@code 0x00} as the remaining
   * most-significant bytes.
   *
   * @since 14.0 (since 11.0 as {@code Hashing.padToLong(HashCode)})
   */
  public abstract long padToLong();

  /**
   * Returns the value of this hash code as a byte array. The caller may modify the byte array;

   * value with {@code asBytes()} as the least-significant bytes and {@code 0x00} as the remaining
   * most-significant bytes.
   *
   * @since 14.0 (since 11.0 as {@code Hashing.padToLong(HashCode)})
   */
  public abstract long padToLong();

  /**
   * Returns the value of this hash code as a byte array. The caller may modify the byte array;

    String toString = "name";
    HashFunction func = new ChecksumHashFunction(supplier, 32, toString);
    assertEquals(toString, func.toString());
    assertEquals(value, func.hashBytes(bytes).padToLong());
  }

  private static void assertHash32(
      int expected, ImmutableSupplier<Checksum> supplier, String input) {
    byte[] bytes = HashTestUtils.ascii(input);
    String toString = "name";

   *
   * <p>To get the {@code long} value equivalent to {@link Checksum#getValue()} for a {@code
   * HashCode} produced by this function, use {@link HashCode#padToLong()}.
   *
   * <p>This function is best understood as a <a
   * href="https://en.wikipedia.org/wiki/Checksum">checksum</a> rather than a true <a
   * href="https://en.wikipedia.org/wiki/Hash_function">hash function</a>.