A callback interface used to signify that a transaction of events have been
received and complete. A common usage pattern is to process a set of events
before publishing/exposing state changes outside of the Static Event
Processor. An example would be a set of bank transfers broken into separate
events:
- DeleteEvent - delete amount from account A
- AddEvent - add to account B from A
- DeleteEvent - delete amount from account C
- AddEvent - add to account B from C
- AddEvent - add to account A from D
- DeleteEvent - delete amount from account D
- batchEnd() - publish updated accounts for A,B,C,D
The batchPause callback is used to tell the static event processor more
messages are expected but have not been received yet. For example we may know
the size of a network batchPaquse allows the static event processor to take
optional actions if waiting for the batch to be completed.