Same as get(key).getOrElse(0L) Note if a counter is never incremented, get returns None.
Same as get(key).getOrElse(0L) Note if a counter is never incremented, get returns None. But you can't tell 0L that comes from None vs. a counter that was incremented then decremented.
This represents the counters portion of the JobStats that are returned. Counters are just a vector of longs with counter name, group keys.