new_contents: #!/usr/bin/env python3
  
  # Install the tulip/asyncio reactor:
  from txtulip.reactor import install
  install()
  
  from twisted.internet.protocol import Protocol, Factory
  from twisted.internet import reactor
  
  
  class Echo(Protocol):
      def dataReceived(self, data):
          self.transport.write(data)
  
  
  
  def main():
      reactor.listenTCP(8000, Factory.forProtocol(Echo))
      reactor.run()
  
  
  
  if __name__ == '__main__':
      main()
  
subject: Add an example.