presto-elasticsearch/src/main/java/io/prestosql/elasticsearch/client/SearchShardsResponse.java/Shard/Shard
class Shard:        @JsonCreator
        public Shard(
                @JsonProperty("shard") int shard,
                @JsonProperty("primary") boolean primary,
                @JsonProperty("node") String node)
        {
            this.shard = shard;
            this.primary = primary;
            this.node = requireNonNull(node, "node is null");
        }