code: def get_stats(self, pattern):
          
          if not self.cache:
              return
          key_list = self.cache.get(Conf.Q_STAT)
          if not key_list or len(key_list) == 0:
              return []
          stats = []
          for key in key_list:
              stat = self.cache.get(key)
              if stat:
                  stats.append(stat)
              else:
                  key_list.remove(key)
          self.cache.set(Conf.Q_STAT, key_list)
          return stats
docs: Returns a list of all cluster stats from the cache provider
          :type pattern: str
          :return: a list of Stats