code: def on_finish(self):
          
          super(StatsdMixin, self).on_finish()
          key = '%s.%s.%s.%s' % (self.__module__,
                                 self.__class__.__name__,
                                 self.request.method, self._status_code)
          LOGGER.info('Processing %s', key)
          self.statsd_incr(key)
          self.statsd_add_timing(key, self.request.request_time() * 1000)
docs: Invoked once the request has been finished. Increment a counter
          created in the format:
  
              package[.module].Class.METHOD.STATUS
              tornado.web.RequestHandler.GET.200