checkHmac(expected, Hashing.hmacMd5(key), data);
  }

  private static void checkHmac(String expected, HashFunction hashFunc, byte[] data) {
    assertEquals(HashCode.fromString(expected), hashFunc.hashBytes(data));
  }

  private static byte[] fillByteArray(int size, int toFillWith) {
    byte[] array = new byte[size];
    Arrays.fill(array, (byte) toFillWith);

  private enum HashMethod {
    MESSAGE_DIGEST_API() {
      @Override
      public byte[] hash(Algorithm algorithm, byte[] input) {
        MessageDigest md = algorithm.getMessageDigest();
        md.update(input);
        return md.digest();
      }
    },
    HASH_FUNCTION_DIRECT() {
      @Override
      public byte[] hash(Algorithm algorithm, byte[] input) {
        return algorithm.getHashFunction().hashBytes(input).asBytes();
      }

   * @since 8.0
   */
  public static final byte SP = 32;

  /**
   * Alternate name for {@link #SP}.
   *
   * @since 8.0
   */
  public static final byte SPACE = 32;

  /**
   * Delete: This character is used primarily to "erase" or "obliterate" erroneous or unwanted
   * characters in perforated tape.
   *
   * @since 8.0
   */
  public static final byte DEL = 127;

  /**

  /**
   * @deprecated This method is dangerous as it discards the high byte of every character. For
   *     UTF-8, use {@code write(s.getBytes(StandardCharsets.UTF_8))}.
   */
  @Deprecated
  @Override
  void writeBytes(String s);

  /** Returns the contents that have been written to this instance, as a byte array. */
  byte[] toByteArray();

    assertThat(Shorts.toByteArray((short) 0xFEDC)).isEqualTo(new byte[] {(byte) 0xFE, (byte) 0xDC});
  }

  @GwtIncompatible // Shorts.fromByteArray
  public void testFromByteArray() {
    assertThat(Shorts.fromByteArray(new byte[] {0x23, 0x45})).isEqualTo((short) 0x2345);
    assertThat(Shorts.fromByteArray(new byte[] {(byte) 0xFE, (byte) 0xDC}))
        .isEqualTo((short) 0xFEDC);

    PrimitiveSink sink = mock(PrimitiveSink.class);
    OutputStream out = Funnels.asOutputStream(sink);
    byte[] bytes = {1, 2, 3, 4};
    out.write(255);
    out.write(bytes);
    out.write(bytes, 1, 2);
    verify(sink).putByte((byte) 255);
    verify(sink).putBytes(bytes);
    verify(sink).putBytes(bytes, 1, 2);
  }

  public void testSerialization() {
    assertSame(

              0x13579bdf,
              null,
              "df9b5713"),
          new ExpectedHashCode(
              new byte[] {(byte) 0xcd, (byte) 0xab, (byte) 0x00, (byte) 0x00},
              0x0000abcd,
              null,
              "cdab0000"),
          new ExpectedHashCode(
              new byte[] {
                (byte) 0xef, (byte) 0xcd, (byte) 0xab, (byte) 0x00,

  }

  MessageDigestHashFunction(String algorithmName, int bytes, String toString) {
    this.toString = checkNotNull(toString);
    this.prototype = getMessageDigest(algorithmName);
    int maxLength = prototype.getDigestLength();
    checkArgument(
        bytes >= 4 && bytes <= maxLength, "bytes (%s) must be >= 4 and < %s", bytes, maxLength);
    this.bytes = bytes;
    this.supportsClone = supportsClone(prototype);
  }

   *   <li>The space character " " is converted into a plus sign "+".
   *   <li>All other characters are converted into one or more bytes using UTF-8 encoding and each
   *       byte is then represented by the 3-character string "%XY", where "XY" is the two-digit,
   *       uppercase, hexadecimal representation of the byte value.
   * </ul>
   *
   * <p>This escaper is suitable for escaping parameter names and values even when <a

  private static final byte ABSENT = -1;

  // Max size is halved due to indexing into double-sized alternatingKeysAndValues
  private static final int BYTE_MAX_SIZE = 1 << (Byte.SIZE - 1); // 2^7 = 128
  private static final int SHORT_MAX_SIZE = 1 << (Short.SIZE - 1); // 2^15 = 32_768

  private static final int BYTE_MASK = (1 << Byte.SIZE) - 1; // 2^8 - 1 = 255