code: public ShardInformation getShardInformation(String shard) {
      ShardInformation shardInformation = shardIndex.get(Objects.requireNonNull(shard, "shard required"));
      if (shardInformation == null) {
        shardInformation = createShardInformation(shard);
      }
      return shardInformation;
    }
docs: Gets the shard information.
  
  @param shard
  the shard
  @return the shard information