presto-main/src/main/java/io/prestosql/execution/executor/PrioritizedSplitRunner.java/PrioritizedSplitRunner/compareTo
class PrioritizedSplitRunner:    @Override
    public int compareTo(PrioritizedSplitRunner o)
    {
        int result = Long.compare(priority.get().getLevelPriority(), o.getPriority().getLevelPriority());
        if (result != 0) {
            return result;
        }

        return Long.compare(workerId, o.workerId);
    }