presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/RaptorBucketFunction.java/RaptorBucketFunction/RaptorBucketFunction
class RaptorBucketFunction:    public RaptorBucketFunction(int bucketCount, List<Type> types)
    {
        checkArgument(bucketCount > 0, "bucketCount must be at least one");
        this.bucketCount = bucketCount;
        this.functions = types.stream()
                .map(RaptorBucketFunction::getHashFunction)
                .toArray(HashFunction[]::new);
    }