presto-main/src/main/java/io/prestosql/operator/aggregation/builder/InMemoryHashAggregationBuilder.java/InMemoryHashAggregationBuilder/evaluate
class InMemoryHashAggregationBuilder:        public void evaluate(int groupId, BlockBuilder output)
        {
            if (step.isOutputPartial()) {
                aggregation.evaluateIntermediate(groupId, output);
            }
            else {
                aggregation.evaluateFinal(groupId, output);
            }
        }