/**
     * Sends a request to the remote endpoint.
     *
     * @param request the request to send
     * @throws IOException if an I/O error occurs
     */
    protected abstract void doSend(Request request) throws IOException;

    /**
     * Receives a response from the remote endpoint.
     *
     * @param response the response object to populate
     * @throws IOException if an I/O error occurs

      source: Buffer,
      byteCount: Long,
    ) {
      val toRead = minOf(remainingByteCount, byteCount)
      if (toRead > 0L) {
        source.read(buffer, toRead)
      }
      val toSkip = byteCount - toRead
      if (toSkip > 0L) {
        source.skip(toSkip)
      }
      remainingByteCount -= toRead
      receivedByteCount += byteCount
    }

    @Throws(IOException::class)

   *
   * @return the source of this event.
   */
  public Object getSource() {
    return source;
  }

  /**
   * Returns the wrapped, 'dead' event, which the system was unable to deliver to any registered
   * subscriber.
   *
   * @return the 'dead' event that could not be delivered.
   */
  public Object getEvent() {
    return event;
  }

  @Override
  public String toString() {

            if (recvException != null) {
                throw recvException;
            }
            return peekedKey;
        }

        @Override
        protected void doSend(Request request) throws IOException {
            if (sendException != null) {
                throw sendException;
            }
        }

        @Override

 * worry about being reentrant, unless also called from outside the EventBus.
 *
 * <h2>Dead Events</h2>
 *
 * <p>If an event is posted, but no registered subscribers can accept it, it is considered "dead."
 * To give the system a second chance to handle dead events, they are wrapped in an instance of
 * {@link DeadEvent} and reposted.
 *

    // A String -- an event for which no one has registered.
    bus.post(EVENT);

    List<DeadEvent> events = catcher.getEvents();
    assertEquals("One dead event should be delivered.", 1, events.size());
    assertEquals("The dead event should wrap the original event.", EVENT, events.get(0).getEvent());
  }

  public void testDeadEventPosting() {
    GhostCatcher catcher = new GhostCatcher();

    // A String -- an event for which no one has registered.
    bus.post(EVENT);

    List<DeadEvent> events = catcher.getEvents();
    assertEquals("One dead event should be delivered.", 1, events.size());
    assertEquals("The dead event should wrap the original event.", EVENT, events.get(0).getEvent());
  }

  public void testDeadEventPosting() {
    GhostCatcher catcher = new GhostCatcher();

      // Fail fast if there's no response queued up.
      return failFastResponse!!
    }

    val result = responseQueue.take()

    // If take() returned because we're shutting down, then enqueue another dead letter so that any
    // other threads waiting on take() will also return.
    if (result == DEAD_LETTER) responseQueue.add(DEAD_LETTER)

    return result
  }

         * in sbuf will be preserved for copying into BUF in doRecv().
         */

        return key;
    }

    @Override
    protected void doSend(final Request request) throws IOException {
        synchronized (BUF) {
            ServerMessageBlock smb = (ServerMessageBlock) request;
            final int n = smb.encode(BUF, 4);

				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, 15)
			}

			// Set tcp user timeout in addition to the keep-alive - tcp-keepalive is not enough to close a socket
			// with dead end because tcp-keepalive is not fired when there is data in the socket buffer.
			//    https://blog.cloudflare.com/when-tcp-sockets-refuse-to-die/