code: func (api *API) MaxShards(ctx context.Context) map[string]uint64 {
  	span, _ := tracing.StartSpanFromContext(ctx, "API.MaxShards")
  	defer span.Finish()
  
  	m := make(map[string]uint64)
  	for k, v := range api.holder.availableShardsByIndex() {
  		m[k] = v.Max()
  	}
  	return m
  }
docs: // MaxShards returns the maximum shard number for each index in a map.
  // TODO (2.0): This method has been deprecated. Instead, use
  // AvailableShardsByIndex.