}
        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 && (byte) 0xA0 <= byte2)
            // Third byte trailing-byte test.
            || bytes[index++] > (byte) 0xBF) {
          return false;

// javadoc?
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Bytes {
  private Bytes() {}

  /**
   * Returns a hash code for {@code value}; equal to the result of invoking {@code ((Byte)
   * value).hashCode()}.
   *
   * <p><b>Java 8+ users:</b> use {@link Byte#hashCode(byte)} instead.
   *
   * @param value a primitive {@code byte} value
   * @return a hash code for the value
   */

	return Map(c.ToTitle, s)
}

// ToValidUTF8 treats s as UTF-8-encoded bytes and returns a copy with each run of bytes
// representing invalid UTF-8 replaced with the bytes in replacement, which may be empty.
func ToValidUTF8(s, replacement []byte) []byte {
	b := make([]byte, 0, len(s)+len(replacement))
	invalid := false // previous byte was from an invalid UTF-8 sequence
	for i := 0; i < len(s); {

              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,

              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,

                new byte[] {(byte) 2, (byte) 3, (byte) 4}))
        .isEqualTo(2);
    assertThat(
            Bytes.indexOf(
                new byte[] {(byte) 2, (byte) 2, (byte) 3, (byte) 4, (byte) 2, (byte) 3, (byte) 4},
                new byte[] {(byte) 2, (byte) 3, (byte) 4}))
        .isEqualTo(1);
    assertThat(
            Bytes.indexOf(
                new byte[] {(byte) 4, (byte) 3, (byte) 2},

                new byte[] {(byte) 2, (byte) 3, (byte) 4}))
        .isEqualTo(2);
    assertThat(
            Bytes.indexOf(
                new byte[] {(byte) 2, (byte) 2, (byte) 3, (byte) 4, (byte) 2, (byte) 3, (byte) 4},
                new byte[] {(byte) 2, (byte) 3, (byte) 4}))
        .isEqualTo(1);
    assertThat(
            Bytes.indexOf(
                new byte[] {(byte) 4, (byte) 3, (byte) 2},

    public int bits() {
      return 64;
    }

    @Override
    public byte[] asBytes() {
      return new byte[] {
        (byte) hash,
        (byte) (hash >> 8),
        (byte) (hash >> 16),
        (byte) (hash >> 24),
        (byte) (hash >> 32),
        (byte) (hash >> 40),
        (byte) (hash >> 48),
        (byte) (hash >> 56)
      };
    }

    @Override
    public int asInt() {

    private byte[] bytes;

    public AppendableByteSource(byte[] initialBytes) {
      this.bytes = initialBytes.clone();
    }

    @Override
    public InputStream openStream() {
      return new In();
    }

    public void append(byte[] b) {
      byte[] newBytes = Arrays.copyOf(bytes, bytes.length + b.length);

		t.Fatal(err)
	}
	if err := w.Close(); err != nil {
		t.Fatal(err)
	}
	b := buf.Bytes()

	var sig [4]byte
	binary.LittleEndian.PutUint32(sig[:], uint32(fileHeaderSignature))

	idx := bytes.Index(b, sig[:])
	if idx == -1 {
		t.Fatal("file header not found")
	}
	b = b[idx:]

	if !bytes.Equal(b[6:10], []byte{0, 0, 0, 0}) { // FileHeader.Flags: 0, FileHeader.Method: 0