presto-main/src/main/java/io/prestosql/operator/aggregation/multimapagg/GroupedMultimapAggregationState.java/GroupedMultimapAggregationState/accept
class GroupedMultimapAggregationState:    @Override
    protected final void accept(MultimapAggregationStateConsumer consumer, PageBuilder pageBuilder, int currentPosition)
    {
        consumer.accept(pageBuilder.getBlockBuilder(KEY_CHANNEL), pageBuilder.getBlockBuilder(VALUE_CHANNEL), currentPosition);
    }