docs: def _emit(self, event):
          """
          If the given event is a stat event, send a I{StatUpdate} command.
          """
          if (event.get('interface') is not iaxiom.IStatEvent and
              'athena_send_messages' not in event and
              'athena_received_messages' not in event):
              return
  
          out = []
          for k, v in event.iteritems():
              if k in ('system', 'message', 'interface', 'isError'):
                  continue
              if not isinstance(v, unicode):
                  v = str(v).decode('ascii')
              out.append(dict(key=k.decode('ascii'), value=v))
          self.callRemote(StatUpdate, data=out)