}
        int byte2 = bytes[index++];
        if (byte2 > (byte) 0xBF
            // Overlong? 5 most significant bits must not all be zero.
            || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
            // Check for illegal surrogate codepoints.
            || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
            // Third byte trailing-byte test.
            || bytes[index++] > (byte) 0xBF) {
          return false;

    hasher = HASH_FN.newHasher();
    hasher
        .putByte((byte) 0x01)
        .putByte((byte) 0x01)
        .putByte((byte) 0x00)
        .putByte((byte) 0x01)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00);
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();

    hasher = HASH_FN.newHasher();
    hasher
        .putByte((byte) 0x01)
        .putByte((byte) 0x01)
        .putByte((byte) 0x00)
        .putByte((byte) 0x01)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00);
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();

    hasher = HASH_FN.newHasher();
    hasher
        .putByte((byte) 0x01)
        .putByte((byte) 0x01)
        .putByte((byte) 0x00)
        .putByte((byte) 0x01)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00)
        .putByte((byte) 0x00);
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();

      Byte[] suffix = {(byte) 86, (byte) 99};
      Byte[] all = concat(concat(prefix, elements), suffix);
      return asList(all).subList(2, elements.length + 2);
    }
  }

  private static Byte[] concat(Byte[] left, Byte[] right) {
    Byte[] result = new Byte[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);
    System.arraycopy(right, 0, result, left.length, right.length);

   * byte order.
   *
   * @return the next four bytes of the input stream, interpreted as an {@code int} in little-endian
   *     byte order
   * @throws IOException if an I/O error occurs
   */
  @CanIgnoreReturnValue // to skip some bytes
  @Override
  public int readInt() throws IOException {
    byte b1 = readAndCheckByte();
    byte b2 = readAndCheckByte();
    byte b3 = readAndCheckByte();

    assertCrc(0x62a8ab43, fulls);
  }

  public void testFull100() {
    // Test 100 byte array of 0xFF.
    byte[] fulls = new byte[100];
    Arrays.fill(fulls, (byte) 0xFF);
    assertCrc(0xbc753add, fulls);
  }

  public void testAscending() {
    // Test 32 byte arrays of ascending.
    byte[] ascending = new byte[32];
    for (int i = 0; i < 32; i++) {
      ascending[i] = (byte) i;
    }

    assertCrc(0x62a8ab43, fulls);
  }

  public void testFull100() {
    // Test 100 byte array of 0xFF.
    byte[] fulls = new byte[100];
    Arrays.fill(fulls, (byte) 0xFF);
    assertCrc(0xbc753add, fulls);
  }

  public void testAscending() {
    // Test 32 byte arrays of ascending.
    byte[] ascending = new byte[32];
    for (int i = 0; i < 32; i++) {
      ascending[i] = (byte) i;
    }

  public void testBytes() {
    TestHasher hasher = new TestHasher(); // byte order insignificant here
    byte[] expected = {1, 2, 3, 4, 5, 6, 7, 8};
    hasher.putByte((byte) 1);
    hasher.putBytes(new byte[] {2, 3, 4, 5, 6});
    hasher.putByte((byte) 7);
    hasher.putBytes(new byte[] {});
    hasher.putBytes(new byte[] {8});
    hasher.assertBytes(expected);
  }

  public void testShort() {

  public void testBytes() {
    TestHasher hasher = new TestHasher(); // byte order insignificant here
    byte[] expected = {1, 2, 3, 4, 5, 6, 7, 8};
    hasher.putByte((byte) 1);
    hasher.putBytes(new byte[] {2, 3, 4, 5, 6});
    hasher.putByte((byte) 7);
    hasher.putBytes(new byte[] {});
    hasher.putBytes(new byte[] {8});
    hasher.assertBytes(expected);
  }

  public void testShort() {