public final class FollowerInitialSyncUpStatus
extends Object
The FollowerInitialSyncUpStatus is sent by a Follower to inform any RaftActor subclass whether the Follower
is at least at the same commitIndex as the Leader was when it sent the follower the very first heart beat.
This status can be used to determine if a Follower has caught up with the current Leader in an upgrade scenario
for example.