TF_RETURN_IF_ERROR(
      CheckABI(ops->filesystem_ops_abi, TF_FILESYSTEM_OPS_ABI, "filesystem"));

  if (ops->random_access_file_ops != nullptr)
    TF_RETURN_IF_ERROR(CheckABI(ops->random_access_file_ops_abi,
                                TF_RANDOM_ACCESS_FILE_OPS_ABI,
                                "random access file"));

  if (ops->writable_file_ops != nullptr)
    TF_RETURN_IF_ERROR(CheckABI(ops->writable_file_ops_abi,

    val s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
    for (i in s.indices) {
      assertRoundTrip(s.substring(0, i).encodeUtf8())
    }
    val random = Random(123456789L)
    val buf = ByteArray(4096)
    random.nextBytes(buf)
    assertRoundTrip(buf.toByteString())
  }

  private fun assertRoundTrip(data: ByteString) {
    val encodeBuffer = Buffer()
    encode(data, encodeBuffer)

  // zero effect on the behavior of the WebSocket API which is why tests are only written once
  // from the perspective of a single peer.
  private val random = Random(0)
  private val client2Server = Pipe(8192L)
  private val server2client = Pipe(8192L)
  private val taskFaker = TaskFaker()
  private val client = TestStreams(true, taskFaker, server2client, client2Server)

    if (slice && bytes.length > 0) {
      // test a random slice() of the ByteSource
      Random random = new Random();
      byte[] expected = factory.getExpected(bytes);
      // if expected.length == 0, off has to be 0 but length doesn't matter--result will be empty
      int off = expected.length == 0 ? 0 : random.nextInt(expected.length);
      int len = expected.length == 0 ? 4 : random.nextInt(expected.length - off);

    hasher.putChar((char) 0x0201);
    hasher.assertBytes(new byte[] {1, 2});
  }

  public void testString() {
    Random random = new Random();
    for (int i = 0; i < 100; i++) {
      byte[] bytes = new byte[64];
      random.nextBytes(bytes);
      String s = new String(bytes, UTF_16LE); // so all random strings are valid
      assertEquals(
          new TestHasher().putUnencodedChars(s).hash(),

  }

  private static final Random RANDOM = new Random(42);

  public void testLength() {
    assertThat(ImmutableIntArray.of().length()).isEqualTo(0);
    assertThat(ImmutableIntArray.of(0).length()).isEqualTo(1);
    assertThat(ImmutableIntArray.of(0, 1, 3).length()).isEqualTo(3);
    assertThat(ImmutableIntArray.of(0, 1, 3).subArray(1, 1).length()).isEqualTo(0);

	const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
	// seeding the random number generator.
	rand.Seed(UTCNow().UnixNano())
	// pick a character randomly.
	return []byte{letterBytes[rand.Intn(len(letterBytes))]}
}

// picks a random byte and repeats it to size bytes.
func generateBytesData(size int) []byte {
	// repeat the random character chosen size
	return bytes.Repeat(getRandomByte(), size)
}

    charset = Charset.forName(charsetName);
    StringBuilder sb = new StringBuilder();
    Random random = new Random(0xdeadbeef); // for unpredictable but reproducible behavior
    sb.ensureCapacity(size);
    for (int k = 0; k < size; k++) {
      // [9-127) includes all ascii non-control characters
      sb.append((char) (random.nextInt(127 - 9) + 9));
    }
    String string = sb.toString();
    sb.setLength(0);

    charset = Charset.forName(charsetName);
    StringBuilder sb = new StringBuilder();
    Random random = new Random(0xdeadbeef); // for unpredictable but reproducible behavior
    sb.ensureCapacity(size);
    for (int k = 0; k < size; k++) {
      // [9-127) includes all ascii non-control characters
      sb.append((char) (random.nextInt(127 - 9) + 9));
    }
    String string = sb.toString();
    sb.setLength(0);

    if (slice && bytes.length > 0) {
      // test a random slice() of the ByteSource
      Random random = new Random();
      byte[] expected = factory.getExpected(bytes);
      // if expected.length == 0, off has to be 0 but length doesn't matter--result will be empty
      int off = expected.length == 0 ? 0 : random.nextInt(expected.length);
      int len = expected.length == 0 ? 4 : random.nextInt(expected.length - off);