abstract int writeDataWireFormat(byte[] dst, int dstIndex);

    abstract int readSetupWireFormat(byte[] buffer, int bufferIndex, int len);

    abstract int readParametersWireFormat(byte[] buffer, int bufferIndex, int len);

    abstract int readDataWireFormat(byte[] buffer, int bufferIndex, int len);

    @Override
    public String toString() {

            byte[] buffer = new byte[20];

            int bytesRead = Transport.readn(is, buffer, 0, 5);
            assertEquals(5, bytesRead);
            assertArrayEquals("Hello".getBytes(), java.util.Arrays.copyOfRange(buffer, 0, 5));
        }

        @Test
        @DisplayName("readn should throw IOException when buffer too short")
        void shouldThrowWhenBufferTooShort() {

    /**
     * Appends the string representation of an {@link Element}.
     *
     * @param element
     *            The element. Must not be {@literal null}.
     * @param buf
     *            The string buffer. Must not be {@literal null}.
     */
    public static void appendElement(final Element element, final StringBuilder buf) {
        assertArgumentNotNull("element", element);
        assertArgumentNotNull("buf", buf);

      to.append(buf);
      total += buf.remaining();
      Java8Compatibility.clear(buf);
    }
    return total;
  }

  // TODO(lukes): consider allowing callers to pass in a buffer to use, some callers would be able
  // to reuse buffers, others would be able to size them more appropriately than the constant
  // defaults

  /**
   * Copies all characters between the {@link Reader} and {@link StringBuilder} objects. Does not

   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)
    val source: Source =
      object : Source {
        var closed = false

        override fun close() {
          closed = true
        }

        override fun read(
          sink: Buffer,
          byteCount: Long,
        ): Long {

    }

    @Test
    @DisplayName("Test buffer modifications are reflected")
    void testBufferModifications() {
        // Since the class returns the same array reference, modifications will be reflected
        byte[] requestBuffer = negotiation.getRequestRaw();
        byte[] responseBuffer = negotiation.getResponseRaw();

        // Modify the buffers
        requestBuffer[0] = (byte) 0xFF;

        return 0;
    }

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

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

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

    @Override

        return 0;
    }

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

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

    @Override
    int readDataWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        if (pipe.pipeIn != null) {

            assertNotNull(bufferManager, "Buffer manager should be created");

            // Test buffer allocation for data transfer
            RdmaMemoryRegion sendBuffer = bufferManager.getSendRegion(8192);
            assertNotNull(sendBuffer, "Send buffer should be allocated");
            assertTrue(sendBuffer.getSize() >= 8192, "Send buffer should be at least 8KB");

                totalWritten += written;
            }

            // Update original buffer position
            buffer.position(buffer.position() + totalWritten);

            log.debug("TCP RDMA write completed: {} bytes", totalWritten);
            return totalWritten;

        } catch (IOException e) {
            state = RdmaConnectionState.ERROR;