new_contents: from flask import Flask, request
  from wsgi_party import WSGIParty, PartylineConnector
  
  
  class PartylineFlask(Flask, PartylineConnector):
      def __init__(self, import_name, *args, **kwargs):
          super(PartylineFlask, self).__init__(import_name, *args, **kwargs)
          self.add_url_rule(WSGIParty.invite_path, endpoint='partyline',
                            view_func=self.join_party_wrapper)
  
      def join_party_wrapper(self, request=request):
          """A simple wrapper to support Flask's request pattern."""
          return self.join_party(request)
  
  
  # Demonstrate.
  root = PartylineFlask(__name__)
  one = PartylineFlask(__name__)
  two = PartylineFlask(__name__)
  
  root.debug = True
  one.debug = True
  two.debug = True
  
  one.config['APPLICATION_ROOT'] = '/one'
  two.config['APPLICATION_ROOT'] = '/two'
  
  application = WSGIParty(root, {
      '/one': one,
      '/two': two,
  })
  
  
  if __name__ == '__main__':
      import os
      from werkzeug.serving import run_simple
      # Bind to PORT if defined, otherwise default to 5000.
      port = int(os.environ.get('PORT', 5000))
      run_simple('0.0.0.0', port, application, use_reloader=True)
  
subject: Add Flask example.