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