old_contents: from ..precomputed.sharding import ShardingSpecification, ShardReader
  
  class GrapheneShardReader(ShardReader):
    def compute_shard_location(self, label):
      shard_loc = self.spec.compute_shard_location(label)
      chunk_id = self.meta.meta.decode_chunk_id_number(label)
      filename = str(chunk_id) + '-' + str(shard_loc.shard_number) + '.shard'
      return (filename, shard_loc.minishard_number)
  
  
   
new_contents: from ..precomputed.sharding import ShardingSpecification, ShardReader
  
  class GrapheneShardReader(ShardReader):
    def compute_shard_location(self, label):
      shard_loc = self.spec.compute_shard_location(label)
      chunk_pos_num = self.meta.meta.decode_chunk_postion_number(label)
      filename = str(chunk_pos_num) + '-' + str(shard_loc.shard_number) + '.shard'
      return (filename, shard_loc.minishard_number)
  
  
   
subject: use correct function for chunk position