presto-main/src/main/java/io/prestosql/sql/planner/NodePartitionMap.java/NodePartitionMap/getNode
class NodePartitionMap:    public InternalNode getNode(Split split)
    {
        int bucket = splitToBucket.applyAsInt(split);
        int partition = bucketToPartition[bucket];
        return requireNonNull(partitionToNode.get(partition));
    }