code: public final boolean isOutCommitted()
    {
      OutHttpApp stream = out();
      
      if (stream.isCommitted()) {
        return true;
      }
  
      // server/05a7
      if (_contentLengthOut > 0 && _contentLengthOut <= stream.contentLength()) {
        return true;
      }
  
      return false;
    }
docs: Returns true if some data has been sent to the browser.