presto-main/src/main/java/io/prestosql/operator/aggregation/AbstractGroupCollectionAggregationState.java/AbstractGroupCollectionAggregationState/getEstimatedSize
class AbstractGroupCollectionAggregationState:    @Override
    public long getEstimatedSize()
    {
        return INSTANCE_SIZE +
                headBlockIndex.sizeOf() +
                headPosition.sizeOf() +
                tailBlockIndex.sizeOf() +
                tailPosition.sizeOf() +
                nextBlockIndex.sizeOf() +
                nextPosition.sizeOf() +
                groupEntryCount.sizeOf() +
                valueBlocksRetainedSizeInBytes +
                // valueBlocksRetainedSizeInBytes doesn't contain the current block builder
                currentPageBuilder.getRetainedSizeInBytes();
    }