private static Map<String, Object> toMap(Iterable<Bucket> buckets) {
      return StreamSupport.stream(buckets.spliterator(), false)
              .collect(LinkedHashMap::new,
                      (m, v) -> m.put(v.getName(), v.key()),
                      LinkedHashMap::putAll);
    }
Identifies a calcite row (as in relational algebra)
criteria/elasticsearch/src/org/immutables/criteria/elasticsearch/Json.java