code: def do_rating_by_request(parser, token):
      
      
      bits = token.contents.split()
      if len(bits) != 6:
          raise template.TemplateSyntaxError("'%s' tag takes exactly five arguments" % bits[0])
      if bits[2] != 'on':
          raise template.TemplateSyntaxError("second argument to '%s' tag must be 'on'" % bits[0])
      if bits[4] != 'as':
          raise template.TemplateSyntaxError("fourth argument to '%s' tag must be 'as'" % bits[0])
      return RatingByRequestNode(bits[1], bits[3], bits[5])
docs: Retrieves the ``Vote`` cast by a user on a particular object and
      stores it in a context variable. If the user has not voted, the
      context variable will be 0.
      
      Example usage::
      
          {% rating_by_request request on instance as vote %}