old_contents: from pyramid.events import NewRequest
  from pyramid.events import subscriber
  
  
  @subscriber(NewRequest)
  def mysubscriber(event):
      # rewrite prefix if X-Script-Name header is present
      script_name = event.request.headers.get('X_SCRIPT_NAME', '')
      if script_name:
          event.request.environ['SCRIPT_NAME'] = script_name
          path_info = event.request.environ['PATH_INFO']
          if path_info.startswith(script_name):
              event.request.environ['PATH_INFO'] = path_info[len(script_name):]
  
      # make sure http/https can be controller
      scheme = event.request.headers.get('X_SCHEME', '')
      scheme = event.request.headers.get('X_URL_SCHEME', scheme)
      if scheme:
          event.request.environ['wsgi.url_scheme'] = scheme
new_contents: from pyramid.events import NewRequest
  from pyramid.events import subscriber
  
  
  @subscriber(NewRequest)
  def use_prefix(event):
      # rewrite prefix if X-Script-Name header is present
      script_name = event.request.headers.get('X_SCRIPT_NAME', '')
      if script_name:
          event.request.environ['SCRIPT_NAME'] = script_name
          path_info = event.request.environ['PATH_INFO']
          if path_info.startswith(script_name):
              event.request.environ['PATH_INFO'] = path_info[len(script_name):]
  
      # make sure http/https can be controller
      scheme = event.request.headers.get('X_SCHEME', '')
      scheme = event.request.headers.get('X_URL_SCHEME', scheme)
      if scheme:
          event.request.environ['wsgi.url_scheme'] = scheme
subject: rename the event