This is the zero of the ExecutionCounter Monoid
Just gets the counters from the CascadingStats and ignores all the other fields present
Gets just the counters from the JobStats
A Simple wrapper over a Map[StatKey, Long]
This allows us to merge the results of two computations.
This allows us to merge the results of two computations. It just does pointwise addition.
The companion gives several ways to create ExecutionCounters from other CascadingStats, JobStats, or Maps