* @throws IllegalArgumentException if {@code bytes} has fewer than 2 elements
   */
  @GwtIncompatible // doesn't work
  public static char fromByteArray(byte[] bytes) {
    checkArgument(bytes.length >= BYTES, "array too small: %s < %s", bytes.length, BYTES);
    return fromBytes(bytes[0], bytes[1]);
  }

  /**
   * Returns the {@code char} value whose byte representation is the given 2 bytes, in big-endian

   *
   * @since 10.0
   */
  public static final byte MAX_POWER_OF_TWO = (byte) 0x80;

  /**
   * The largest value that fits into an unsigned byte.
   *
   * @since 13.0
   */
  public static final byte MAX_VALUE = (byte) 0xFF;

  private static final int UNSIGNED_MASK = 0xFF;

  /**

   *
   * @throws IllegalArgumentException if {@code bytes} has fewer than 4 elements
   */
  public static int fromByteArray(byte[] bytes) {
    checkArgument(bytes.length >= BYTES, "array too small: %s < %s", bytes.length, BYTES);
    return fromBytes(bytes[0], bytes[1], bytes[2], bytes[3]);
  }

  /**
   * Returns the {@code int} value whose byte representation is the given 4 bytes, in big-endian

  public synchronized void write(int b) throws IOException {
    update(1);
    out.write(b);
  }

  @Override
  public synchronized void write(byte[] b) throws IOException {
    write(b, 0, b.length);
  }

  @Override
  public synchronized void write(byte[] b, int off, int len) throws IOException {
    update(len);
    out.write(b, off, len);
  }

  @Override

  public void testBytes() {
    Sink sink = new Sink(4); // byte order insignificant here
    byte[] expected = {1, 2, 3, 4, 5, 6, 7, 8};
    sink.putByte((byte) 1);
    sink.putBytes(new byte[] {2, 3, 4, 5, 6});
    sink.putByte((byte) 7);
    sink.putBytes(new byte[] {});
    sink.putBytes(new byte[] {8});
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(expected);

  }

  /**
   * Reads all bytes from a file into a byte array.
   *
   * <p><b>{@link java.nio.file.Path} equivalent:</b> {@link java.nio.file.Files#readAllBytes}.
   *
   * @param file the file to read from
   * @return a byte array containing all the bytes from file
   * @throws IllegalArgumentException if the file is bigger than the largest possible byte array
   *     (2^31 - 1)

    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    ObjectOutputStream oos = new ObjectOutputStream(bytes);
    oos.writeObject(map);
    oos.flush();

    int mapSize = bytes.size();
    oos.writeObject(keySet);
    oos.writeObject(values);
    oos.close();

    int finalSize = bytes.size();

    assertThat(finalSize - mapSize).isLessThan(100);

      }
    }

    @Override
    HashCode makeHash(Hasher[] hashers) {
      byte[] bytes = new byte[bits() / 8];
      int i = 0;
      for (Hasher hasher : hashers) {
        HashCode newHash = hasher.hash();
        i += newHash.writeBytesTo(bytes, i, newHash.bits() / 8);
      }
      return HashCode.fromBytesNoCopy(bytes);
    }

    @Override
    public int bits() {
      int bitSum = 0;

      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);

  @J2ktIncompatible
  @GwtIncompatible // serialization
  private static Object reserialize(Object object) throws Exception {
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    new ObjectOutputStream(bytes).writeObject(object);
    return new ObjectInputStream(new ByteArrayInputStream(bytes.toByteArray())).readObject();
  }