presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/PushAggregationThroughOuterJoin.java/PushAggregationThroughOuterJoin/MappedAggregationInfo
class PushAggregationThroughOuterJoin:        public MappedAggregationInfo(AggregationNode aggregationNode, Map<Symbol, Symbol> symbolMapping)
        {
            this.aggregationNode = aggregationNode;
            this.symbolMapping = symbolMapping;
        }