/** Send a ping with the supplied [payload]. */
  @Throws(IOException::class)
  fun writePing(payload: ByteString) {
    writeControlFrame(OPCODE_CONTROL_PING, payload)
  }

  /** Send a pong with the supplied [payload]. */
  @Throws(IOException::class)
  fun writePong(payload: ByteString) {
    writeControlFrame(OPCODE_CONTROL_PONG, payload)
  }

  /**

          }
        } else if (messageOrClose == null) {
          return false // The queue is exhausted.
        }
      }
    }

    try {
      if (pong != null) {
        writer!!.writePong(pong)
      } else if (messageOrClose is Message) {
        val message = messageOrClose
        writer!!.writeMessageFrame(message.formatOpcode, message.data)
        synchronized(this) {

        long MILLISECONDS_BETWEEN_1970_AND_1601 = 11644473600000L;
        writeLong(buffer, 0, (create + MILLISECONDS_BETWEEN_1970_AND_1601) * 10000L);
        writeLong(buffer, 8, (lastAccess + MILLISECONDS_BETWEEN_1970_AND_1601) * 10000L);
        writeLong(buffer, 16, (lastWrite + MILLISECONDS_BETWEEN_1970_AND_1601) * 10000L);
        writeLong(buffer, 24, (change + MILLISECONDS_BETWEEN_1970_AND_1601) * 10000L);

            dos.writeInt(Integer.reverseBytes(10));
            dos.writeLong(Long.reverseBytes(100));

            dos.writeInt(Integer.reverseBytes(PacConstants.SERVER_CHECKSUM));
            dos.writeInt(Integer.reverseBytes(16));
            dos.writeLong(Long.reverseBytes(200));

            dos.writeInt(Integer.reverseBytes(PacConstants.PRIVSVR_CHECKSUM));

    @Test
    @DisplayName("writeULong writes little endian bytes")
    void testWriteULong() {
        byte[] dest = new byte[4];
        NtlmMessage.writeULong(dest, 0, 0x01020304);
        assertArrayEquals(new byte[] { 4, 3, 2, 1 }, dest, "Writer must be little‑endian");
    }

    @Test
    @DisplayName("writeULong handles negative values as unsigned")
    void testWriteULongNegative() {

    }

    @Test
    void testWriteULong() {
        // Test writeULong
        byte[] data = new byte[4];
        ByteBuffer expectedBuffer = ByteBuffer.allocate(4).order(ByteOrder.LITTLE_ENDIAN);

        // Test with a positive value
        int value = 0x12345678;
        NtlmMessage.writeULong(data, 0, value);
        expectedBuffer.putInt(0, value);

        final int offset = readULong(src, index + 4);
        final byte[] buffer = new byte[length];
        System.arraycopy(src, offset, buffer, 0, length);
        return buffer;
    }

    static void writeULong(final byte[] dest, final int offset, final int ulong) {
        dest[offset] = (byte) (ulong & 0xff);
        dest[offset + 1] = (byte) (ulong >> 8 & 0xff);
        dest[offset + 2] = (byte) (ulong >> 16 & 0xff);

            Type2Message.writeULong(truncatedMessage, 8, Type2Message.NTLMSSP_TYPE2);
            // Set empty target name buffer
            Type2Message.writeUShort(truncatedMessage, 12, 0); // length
            Type2Message.writeUShort(truncatedMessage, 14, 0); // max length
            Type2Message.writeULong(truncatedMessage, 16, 48); // offset (past the end)
            // Set flags

            int pos = 0;

            System.arraycopy(NTLMSSP_SIGNATURE, 0, type1, 0, NTLMSSP_SIGNATURE.length);
            pos += NTLMSSP_SIGNATURE.length;

            writeULong(type1, pos, NTLMSSP_TYPE1);
            pos += 4;

            writeULong(type1, pos, flags);
            pos += 4;

            final int domOffOff = writeSecurityBuffer(type1, pos, domain);
            pos += 8;

  @Throws(InterruptedException::class)
  fun writePingAndAwaitPong() {
    writePing()
    awaitPong()
  }

  /** For testing: sends a ping to be awaited with [awaitPong]. */
  @Throws(InterruptedException::class)
  fun writePing() {
    withLock {
      awaitPingsSent++
    }

    // 0x4f 0x4b 0x6f 0x6b is "OKok".
    writePing(false, AWAIT_PING, 0x4f4b6f6b)
  }

  /** For testing: awaits a pong. */