code: public void start()
    {
      _state = _state.toStart();
      
      _bufferCapacity = DEFAULT_SIZE;
      
      _tBuf = TempBuffer.create();
      
      _buffer = _tBuf.buffer();
      _startOffset = bufferStart();
      _offset = _startOffset;
  
      _contentLength = 0;
    }
docs: Starts the response stream.