code: def render_GET(self, request):
          
          request.setHeader(b'accept-ranges', b'bytes')
  
          producer = self.makeProducer(request, self.fileObject)
  
          if request.method == b'HEAD':
              return b''
  
          def done(ign):
              producer.stopProducing()
  
          request.notifyFinish().addCallbacks(done, done)
          producer.start()
          # and make sure the connection doesn't get closed
          return server.NOT_DONE_YET
docs: Begin sending the contents of this L{File} (or a subset of the
          contents, based on the 'range' header) to the given request.