This is great ! I'm glad to see that the odd signatures of MapReduce operators has been definitely deprecated in favor of true `map` and `reduce` functions (re

This is great ! I'm glad to see that the odd signatures of MapReduce operators has been definitely deprecated in favor of true `map` and `reduce` functions (renamed `ParDo` and `Combine`) even if `ParDo` is a `flatmap` (or `bind`) rather than a `map` function. We gain in simplicity and composability. And the long detour by MapReduce and Hadoop seems to take an end in favor of systems like Spark, Flink, Samza and now Cloud Dataflow.