code: def wsgi_proxyfix(factory=None):
      
      def create_wsgi(app, **kwargs):
          wsgi_app = factory(app, **kwargs) if factory else app.wsgi_app
          if app.config.get('WSGI_PROXIES'):
              return ProxyFix(wsgi_app, num_proxies=app.config['WSGI_PROXIES'])
          return wsgi_app
      return create_wsgi
docs: Fix ``REMOTE_ADDR`` based on ``X-Forwarded-For`` headers.
  
      .. note::
  
         You must set ``WSGI_PROXIES`` to the correct number of proxies,
         otherwise you application is susceptible to malicious attacks.
  
      .. versionadded:: 1.0.0