EventTimeStatsAccum Accumulator

EventTimeStatsAccum is a Spark accumulator of EventTimeStats from Longs (i.e. AccumulatorV2[Long, EventTimeStats]) that collects statistics on event time in a streaming batch.

EventTimeStatsAccum takes a EventTimeStats when created.

EventTimeStatsAccum is used exclusively when EventTimeWatermarkExec is executed (and accumulates eventTime values from every row in a streaming batch).