presto-main/src/main/java/io/prestosql/execution/executor/TaskHandle.java/TaskHandle/resetLevelPriority
class TaskHandle:    public synchronized Priority resetLevelPriority()
    {
        long levelMinPriority = splitQueue.getLevelMinPriority(priority.get().getLevel(), scheduledNanos);
        if (priority.get().getLevelPriority() < levelMinPriority) {
            Priority newPriority = new Priority(priority.get().getLevel(), levelMinPriority);
            priority.set(newPriority);
            return newPriority;
        }

        return priority.get();
    }