In a Flink ReduceFunction, there is value1 and value2 and then the returned output. Is there any kind of guarantee that on the next call, value1 is the next value and value2 is the previously combined one or vice-versa? If I wanted to implement a simple way to get the latest value in a window, I’d do

reduce(next, agg) and return next

but if there are no guarantees that doesn’t work.