protected final @Nullable T endOfData() {
    state = State.DONE;
    return null;
  }

  @Override
  public final boolean hasNext() {
    checkState(state != State.FAILED);
    switch (state) {
      case DONE:
        return false;
      case READY:
        return true;
      default:
    }
    return tryToComputeNext();
  }

  private boolean tryToComputeNext() {

     *
     * @return the count of bytes written
     */
    public long getCount() {
        return this.count;
    }

    @Override
    protected int writeParameterWordsWireFormat(final byte[] dst, final int dstIndex) {
        return 0;
    }

    @Override
    protected int writeBytesWireFormat(final byte[] dst, final int dstIndex) {
        return 0;
    }

    @Override

        return 0;
    }

    @Override
    protected int readParametersWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        return 0;
    }

    @Override
    protected int readDataWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        return 0;
    }

    @Override
    public String toString() {

        dstIndex += writeString(path, dst, dstIndex);

        return dstIndex - start;
    }

    @Override
    int writeDataWireFormat(final byte[] dst, final int dstIndex) {
        return 0;
    }

    @Override
    int readSetupWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        return 0;
    }

    @Override

    return doAssertThrows(expectedThrowable, supplier, /* userPassedSupplier= */ true);
  }

  @CanIgnoreReturnValue
  static <T extends Throwable> T assertThrows(
      Class<T> expectedThrowable, ThrowingRunnable runnable) {
    return doAssertThrows(
        expectedThrowable,
        () -> {
          runnable.run();
          return null;
        },

      result.add(value(i))
    }
  }
  return result?.unmodifiable().orEmpty()
}

internal fun Headers.commonIterator(): Iterator<Pair<String, String>> = Array(size) { name(it) to value(it) }.iterator()

internal fun Headers.commonNewBuilder(): Headers.Builder {
  val result = Headers.Builder()
  result.namesAndValues += namesAndValues
  return result
}

        String stderr = stderrFuture.get()
        return new ExecResult(stderr: stderr, stdout: stdout, returnCode: returnCode)
    }

    static String getStdout(String command) {
        ExecResult execResult = exec(command)

        assert execResult.returnCode == 0: "$command failed with return code: $execResult"
        return execResult.stdout
    }

    private CrawlingParameterUtil() {
    }

    /**
     * Retrieves the current thread's {@link UrlQueue} instance.
     *
     * @return the {@link UrlQueue} instance associated with the current thread, or {@code null} if none is set.
     */
    public static UrlQueue<?> getUrlQueue() {
        return URL_QUEUE_THREAD_LOCAL.get();
    }

    /**
     * Sets the URL queue for the current thread. If the provided URL queue is null,

    BALANCED {
      @Override
      Optional<BinaryNode> createTree(int size, Random rng) {
        if (size == 0) {
          return Optional.absent();
        } else {
          int leftChildSize = (size - 1) / 2;
          int rightChildSize = size - 1 - leftChildSize;
          return Optional.of(
              new BinaryNode(
                  rng.nextInt(), createTree(leftChildSize, rng), createTree(rightChildSize, rng)));

    return delegate().offerFirst(e, timeout, unit);
  }

  @Override
  public boolean offerLast(E e, long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().offerLast(e, timeout, unit);
  }

  @Override
  public E takeFirst() throws InterruptedException {
    return delegate().takeFirst();
  }

  @Override