when(mockInputStream.read(any(byte[].class), anyInt(), anyInt())).thenReturn(2) // First read returns 2 bytes
                .thenReturn(2) // Second read returns 2 bytes
                .thenReturn(1); // Third read returns 1 byte

        byte[] buffer = new byte[10];
        int bytesRead = SessionServicePacket.readn(mockInputStream, buffer, 0, 5);

        assertEquals(5, bytesRead);

        return ((src[srcIndex++] & 0x01) << 16) + ((src[srcIndex++] & 0xFF) << 8) + (src[srcIndex++] & 0xFF);
    }

    static int readn(final InputStream in, final byte[] b, final int off, final int len) throws IOException {
        int i = 0, n;

        while (i < len) {
            n = in.read(b, off + i, len - i);
            if (n <= 0) {
                break;
            }
            i += n;
        }

        do {
            if ((n = readn(in, sbuf, 0, 4)) < 4) {
                return null;
            }
        } while (sbuf[0] == (byte) 0x85); /* Dodge NetBIOS keep-alive */
        n = readn(in, sbuf, 4, 32);
        /* read smb header */
        if (n < 32) {
            return null;
        }
        if (LogStream.level >= 4) {
            log.println("New data read: " + this);

            InputStream is = new ByteArrayInputStream("Hi".getBytes());
            byte[] buffer = new byte[10];

            Transport.readn(is, buffer, 0, 2); // Read all
            int bytesRead = Transport.readn(is, buffer, 0, 5); // Try to read more
            assertEquals(0, bytesRead);
        }
    }

    @Nested
    @DisplayName("Resource management tests")

        return ((src[srcIndex++] & 0x01) << 16) + ((src[srcIndex++] & 0xFF) << 8) + (src[srcIndex++] & 0xFF);
    }

    static int readn(final InputStream in, final byte[] b, final int off, final int len) throws IOException {
        int i = 0, n;

        while (i < len) {
            n = in.read(b, off + i, len - i);
            if (n <= 0) {
                break;
            }
            i += n;
        }

    }

    @Override
    protected Long peekKey() throws IOException {
        do {
            if (readn(this.in, this.sbuf, 0, 4) < 4) {
                return null;
            }
        } while (this.sbuf[0] == (byte) 0x85); /* Dodge NetBIOS keep-alive */
        /* read smb header */
        if (readn(this.in, this.sbuf, 4, SmbConstants.SMB1_HEADER_LENGTH) < SmbConstants.SMB1_HEADER_LENGTH) {
            return null;

    static LogStream log = LogStream.getInstance();

    /**
     * Reads exactly len bytes from the input stream into the buffer.
     *
     * @param in the input stream to read from
     * @param b the buffer to read into
     * @param off the offset in the buffer to start writing
     * @param len the number of bytes to read
     * @return the number of bytes actually read
     * @throws IOException if an I/O error occurs
     */

    /**
     * Read bytes from the input stream into a buffer
     *
     * @param in the input stream to read from
     * @param b the buffer to read into
     * @param off the offset in the buffer to start writing
     * @param len the number of bytes to read
     * @return number of bytes read
     * @throws IOException if an I/O error occurs
     */

        int read3 = response.readBytesWireFormat(buffer, 0);

        // Then - all reads should return same result
        assertEquals(4, read1);
        assertEquals(4, read2);
        assertEquals(4, read3);
    }

    @Test
    @DisplayName("Should validate structure size before processing")
    void testStructureSizeValidation() {
        // Given various invalid structure sizes

    byte[] buf1 = createBuffer();
    byte[] buf2 = createBuffer();
    while (true) {
      int read1 = read(in1, buf1, 0, BUFFER_SIZE);
      int read2 = read(in2, buf2, 0, BUFFER_SIZE);
      if (read1 != read2 || !arraysEqual(buf1, buf2, read1)) {
        return false;
      } else if (read1 != BUFFER_SIZE) {
        return true;
      }
    }
  }