docs: def stats_flush(self):
          """
          Periodically flush stats to graphite
          """
          while True:
              try:
                  eventlet.sleep(self.flush_interval)
                  if self.debug:
                      print "seen %d stats so far." % self.stats_seen
                      print "current counters: %s" % self.counters
                  if self.pickle_proto:
                      payload = self.pickle_payload()
                      if payload:
                          for batch in payload:
                              self.report_stats(batch)
                  else:
                      payload = self.plain_payload()
                      if payload:
                          self.report_stats(payload)
              except: # safety net
                  self.logger.critical('Encountered error in stats_flush loop')