presto-main/src/main/java/io/prestosql/sql/planner/planprinter/PlanNodeStats.java/PlanNodeStats/getOperatorInputPositionsAverages
class PlanNodeStats:    public Map<String, Double> getOperatorInputPositionsAverages()
    {
        return operatorInputStats.entrySet().stream()
                .collect(toMap(
                        Map.Entry::getKey,
                        entry -> (double) entry.getValue().getInputPositions() / operatorInputStats.get(entry.getKey()).getTotalDrivers()));
    }