| Class | Description | 
|---|---|
| SparkGroupAlsoByWindowViaWindowSet | An implementation of  GroupByKeyViaGroupByKeyOnly.GroupAlsoByWindowlogic for grouping by windows and controlling
 trigger firings and pane accumulation. | 
| SparkStateInternals<K> | An implementation of  StateInternalsfor the SparkRunner. | 
| SparkTimerInternals | An implementation of  TimerInternalsfor the SparkRunner. | 
| StateAndTimers | State and Timers wrapper. | 
| StateSpecFunctions | A class containing  StateSpecmappingFunctions. |