LeaderAndIsrResponseReceived Controller Event
LeaderAndIsrResponseReceived is a controller event that transition the KafkaController to LeaderAndIsrResponseReceived state.
LeaderAndIsrResponseReceived takes the following to be created:
LeaderAndIsrResponseReceived is enqueued exclusively when AbstractControllerBrokerRequestBatch (ControllerBrokerRequestBatch actually) is requested to sendLeaderAndIsrRequest (and a response has arrived).
Processing LeaderAndIsrResponseReceived
When processed (on the controller-event-thread), KafkaController is requested to processLeaderAndIsrResponseReceived.