Reading this article https://cloud.google.com/blog/products/data-analytics/after-lambda-exactly-once-processing-in-google-cloud-dataflow-part-1
The side effects section says
Cloud Dataflow does not guarantee that this code is run only once per record, whether by the streaming or batch runner. It might run a given record through a user transform multiple times, or it might even run the same record simultaneously on multiple workers; this is necessary to guarantee at-least once processing in the face of worker failures
If I use the GroupIntoBatches transform will the resulting batch be run through a user transform multiple times?
