In Beam a WindowedValue can can contain multiple windows, because an element can be in multiple windows at once (for example, sliding windows). Usually we keep these elements unexpanded, but if the user's doFn observes the window then we have to "explode" the element out, and we run the process function once per window. e.g. if the process function looks like this
@ProcessElement public void process(@Element T e, IntervalWindow w) In SimpleDoFnRunner we do this inside processElement. However I can't find the equivalent code in FnApiDoFnRunner. How does window explosion work in the portable runner? Reuven
