presto-main/src/main/java/io/prestosql/operator/aggregation/builder/SpillableHashAggregationBuilder.java/SpillableHashAggregationBuilder/updateMemory
class SpillableHashAggregationBuilder:    @Override
    public void updateMemory()
    {
        checkState(spillInProgress.isDone());

        if (producingOutput) {
            localRevocableMemoryContext.setBytes(0);
            localUserMemoryContext.setBytes(hashAggregationBuilder.getSizeInMemory());
        }
        else {
            localUserMemoryContext.setBytes(emptyHashAggregationBuilderSize);
            localRevocableMemoryContext.setBytes(hashAggregationBuilder.getSizeInMemory() - emptyHashAggregationBuilderSize);
        }
    }