code: protected void checkOutput()
      {
          if (_out==_realOut)
          {
              if (_bufferedOut==null)
              {
                  _bufferedOut=new ChunkingOutputStream(_realOut,
                                                        _bufferSize,
                                                        _headerReserve,
                                                        false);
                  _bufferedOut.setCommitObserver(this);
                  _bufferedOut.setBypassBuffer(true);
                  _bufferedOut.setFixed(true);
              }
              _out=_bufferedOut;
          }
      }
docs: /* ------------------------------------------------------------