presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/HivePageSinkMetadata.java/JsonSerializableEntry/toMap
class JsonSerializableEntry:        public static <K, V> Map<K, V> toMap(List<JsonSerializableEntry<K, V>> list)
        {
            return list.stream()
                    .collect(Collectors.toMap(JsonSerializableEntry::getKey, JsonSerializableEntry::getValue));
        }