new_contents: #!/usr/bin/env python3
  """Example for aiohttp.web basic server with cookies.
  """
  
  import asyncio
  from aiohttp import web
  
  
  tmpl = '''\
  <html>
      <body>
          <a href="/login">Login</a><br/>
          <a href="/logout">Logout</a><br/>
          {}
      </body>
  </html>'''
  
  
  @asyncio.coroutine
  def root(request):
      resp = web.Response(content_type='text/html')
      resp.text = tmpl.format(request.cookies)
      return resp
  
  
  @asyncio.coroutine
  def login(request):
      resp = web.HTTPFound(location='/')
      resp.set_cookie('AUTH', 'secret')
      return resp
  
  
  @asyncio.coroutine
  def logout(request):
      resp = web.HTTPFound(location='/')
      resp.del_cookie('AUTH')
      return resp
  
  
  @asyncio.coroutine
  def init(loop):
      app = web.Application(loop=loop)
      app.router.add_route('GET', '/', root)
      app.router.add_route('GET', '/login', login)
      app.router.add_route('GET', '/logout', logout)
  
      handler = app.make_handler()
      srv = yield from loop.create_server(handler, '127.0.0.1', 8080)
      print("Server started at http://127.0.0.1:8080")
      return srv, handler
  
  loop = asyncio.get_event_loop()
  srv, handler = loop.run_until_complete(init(loop))
  try:
      loop.run_forever()
  except KeyboardInterrupt:
      loop.run_until_complete(handler.finish_connections())
  
subject: Add example for server-side cookies