docs: def convert(self, request, response, data):
          """
          Performs the desired Conversion.
  
          :param request: The webob Request object describing the
                          request.
          :param response: The webob Response object describing the
                           response.
          :param data: The data dictionary returned by the prepare()
                       method.
  
          :returns: A string, the results of which are the desired
                    conversion.
          """
  
          # Notes are in bark.notes dictionary
          return self.escape(request.environ.get('bark.notes', {}).get(
              self.modifier.param, '-'))