presto-main/src/main/java/io/prestosql/execution/scheduler/NodeAssignmentStats.java/NodeAssignmentStats/getQueuedSplitCountForStage
class NodeAssignmentStats:    public int getQueuedSplitCountForStage(InternalNode node)
    {
        return queuedSplitCountByNode.getOrDefault(node.getNodeIdentifier(), 0) + assignmentCount.getOrDefault(node, 0);
    }