* set a value to {@code null} will result in a {@link NullPointerException}.
   *
   * <p>The returned list maintains the values, but not the identities, of {@code Short} objects
   * written to or read from it. For example, whether {@code list.get(0) == list.get(0)} is true for
   * the returned list is unspecified.
   *
   * <p>The returned list is serializable.
   *

        stack = stack.next;
      }
    }

    private static class RunnableExecutorPair {
      final Runnable runnable;
      final Executor executor;
      // Volatile because this is written on one thread and read on another with no synchronization.
      @Nullable volatile RunnableExecutorPair next;

      RunnableExecutorPair(@Nullable Runnable runnable, @Nullable Executor executor) {

  }

  /** The listeners to notify during a state transition. */
  private final ListenerCallQueue<Listener> listeners = new ListenerCallQueue<>();

  /**
   * The current state of the service. This should be written with the lock held but can be read
   * without it because it is an immutable object in a volatile field. This is desirable so that
   * methods like {@link #state}, {@link #failureCause} and notably {@link #toString} can be run

		dst = binary.LittleEndian.AppendUint32(dst, uint32(h))
	}
	return m.parent.send(m.ctx, dst)
}

// RequestStateless will send a single payload request and stream back results.
// req may not be read/written to after calling.
// TODO: Not implemented
func (m *muxClient) RequestStateless(h HandlerID, req []byte, out chan<- Response) {
	if m.init {
		out <- Response{Err: errors.New("mux client already used")}
	}

}

func (s3Select *S3Select) marshal(buf *bytes.Buffer, record sql.Record) error {
	switch s3Select.Output.format {
	case csvFormat:
		// Use bufio Writer to prevent csv.Writer from allocating a new buffer.
		bufioWriter := bufioWriterPool.Get().(*bufio.Writer)
		defer func() {
			bufioWriter.Reset(xioutil.Discard)
			bufioWriterPool.Put(bufioWriter)
		}()

		bufioWriter.Reset(buf)
		opts := sql.WriteCSVOpts{

				return
			} else if rec != nil {
				stack := debug.Stack()
				logger.Error("panic: \"%s %s\": %v\n%s", r.Method, r.URL, rec, string(stack))
				// Try to write an error response, upstream may not have written header.
				writeErrorResponse(r.Context(), w, errorCodes.ToAPIErr(ErrInternalError), r.URL)
				return
			}
		}()
		h.ServeHTTP(w, r)
	})
}

  }
  /**
   * ReadWriteLock implementation whose read and write locks retain a reference back to this lock.
   * Otherwise, a reference to just the read lock or just the write lock would not suffice to ensure
   * the {@code ReadWriteLock} is retained.
   */
  private static final class WeakSafeReadWriteLock implements ReadWriteLock {
    private final ReadWriteLock delegate;

    WeakSafeReadWriteLock() {

    /*
     * We adjust approxLog10 and approxPow until they're equal to floor(log10(x)) and
     * 10^floor(log10(x)).
     */

    if (approxCmp > 0) {
      /*
       * The code is written so that even completely incorrect approximations will still yield the
       * correct answer eventually, but in practice this branch should almost never be entered, and
       * even then the loop should not run more than once.

        added += q.drainTo(buffer, numElements - added);
        if (added < numElements) { // not enough elements immediately available; will have to poll
          E e; // written exactly once, by a successful (uninterrupted) invocation of #poll
          while (true) {
            try {
              e = q.poll(deadline - System.nanoTime(), NANOSECONDS);
              break;

   *
   * This method is always invoked after [requestBodyStart].
   */
  open fun requestBodyEnd(
    call: Call,
    byteCount: Long,
  ) {
  }

  /**
   * Invoked when a request fails to be written.
   *
   * This method is invoked after [requestHeadersStart] or [requestBodyStart]. Note that request
   * failures do not necessarily fail the entire call.
   */
  open fun requestFailed(
    call: Call,