presto-main/src/main/java/io/prestosql/execution/scheduler/group/DynamicBucketNodeMap.java/DynamicBucketNodeMap/DynamicBucketNodeMap
class DynamicBucketNodeMap:    public DynamicBucketNodeMap(ToIntFunction<Split> splitToBucket, int bucketCount)
    {
        super(splitToBucket);
        checkArgument(bucketCount > 0, "bucketCount must be positive");
        this.bucketCount = bucketCount;
    }