This week's giveaway is in the Cloud/Virtualization forum. We're giving away four copies of Production-Ready Serverless (Operational Best Practices) and have Yan Cui on-line! See this thread for details.
The second sentence of the last paragraph in "Summarizing Statistics" part mentions the properties of IntSummaryStatistics class. I don't think "size" property is relevant, instead "sum" property can be mentioned there.