presto-main/src/main/java/io/prestosql/sql/planner/ExpressionExtractor.java/ExpressionExtractor/visitAggregation
class ExpressionExtractor:        @Override
        public Void visitAggregation(AggregationNode node, Void context)
        {
            for (Aggregation aggregation : node.getAggregations().values()) {
                aggregation.getArguments().forEach(consumer);
            }
            return super.visitAggregation(node, context);
        }