code: public void writeByteBufferPart(byte[] buffer, int offset, int length)
          throws IOException
      {
          while (length > 0) {
              int sublen = length;
  
              if (0x8000 < sublen)
                  sublen = 0x8000;
  
              os.write('b');
              os.write(sublen >> 8);
              os.write(sublen);
  
              os.write(buffer, offset, sublen);
  
              length -= sublen;
              offset += sublen;
          }
      }
docs: Writes a byte buffer to the stream.
  
  <code><pre>
  b b16 b18 bytes
  </pre></code>