presto-hive/src/main/java/io/prestosql/plugin/hive/HiveSplit.java/BucketConversion/BucketConversion
class BucketConversion:        @JsonCreator
        public BucketConversion(
                @JsonProperty("bucketingVersion") BucketingVersion bucketingVersion,
                @JsonProperty("tableBucketCount") int tableBucketCount,
                @JsonProperty("partitionBucketCount") int partitionBucketCount,
                @JsonProperty("bucketColumnHandles") List<HiveColumnHandle> bucketColumnHandles)
        {
            this.bucketingVersion = requireNonNull(bucketingVersion, "bucketingVersion is null");
            this.tableBucketCount = tableBucketCount;
            this.partitionBucketCount = partitionBucketCount;
            this.bucketColumnNames = requireNonNull(bucketColumnHandles, "bucketColumnHandles is null");
        }