docs: def get_slabs_stats(key, value):
          """
          Optional metric handler for 'items' stats
  
          key: "items:<slab_id>:<metric_name>" format
          value: return untouched
  
          Like all optional metric handlers returns metric, tags, value
          """
          slabbed_key = key.split(':')
          tags = []
          if len(slabbed_key) == 2:
              slab_id = slabbed_key[0]
              metric = slabbed_key[1]
              tags = ["slab:{}".format(slab_id)]
          else:
              metric = slabbed_key[0]
  
          return metric, tags, value