old_contents: import asyncio
  from aiohttp import web
  
  from command_line import define, parse_command_line
  
  
  @asyncio.coroutine
  def init_server(loop, ip, port, router=None):
      app = web.Application(loop=loop, router=router)
      srv = yield from loop.create_server(app.make_handler(), str(ip), int(port))
      print("Server started at http://{0}:{1}".format(ip, port))
      return srv
  
  
  def run_server(router=None):
      define('-ip', default='127.0.0.1', type=str, help="used ip for server",
             required=False)
      define('-port', default=8080, type=int, help="listened port for server",
             required=False)
      args = parse_command_line()
      loop = asyncio.get_event_loop()
      server_instance = init_server(loop, args.ip, args.port, router)
      loop.run_until_complete(server_instance)
      loop.run_forever()
  
new_contents: import asyncio
  from aiohttp import web
  
  from command_line import define, parse_command_line
  
  
  @asyncio.coroutine
  def init_server(loop, ip, port, router=None):
      app = web.Application(loop=loop, router=router)
      srv = yield from loop.create_server(app.make_handler(), str(ip), int(port))
      print("Server started at http://{0}:{1}".format(ip, port))
      return srv
  
  
  def run_server(router=None):
      define('-ip', default='127.0.0.1', type=str, help="used ip for server",
             required=False)
      define('-port', default=8080, type=int, help="listened port on the server",
             required=False)
      args = parse_command_line()
      loop = asyncio.get_event_loop()
      server_instance = init_server(loop, args.ip, args.port, router)
      loop.run_until_complete(server_instance)
      loop.run_forever()
  
subject: Update server.py