* Invoked whenever the local shard's leadership role changes.
*
* @param isLeader true if the shard has become leader, false if it has
- * become a follower.
+ * become a follower.
+ * @param hasLeader true if the shard knows about leader ID
*/
- abstract void onLeadershipChange(boolean isLeader);
- abstract void onMessage(M message, boolean isLeader);
+ abstract void onLeadershipChange(boolean isLeader, boolean hasLeader);
+ abstract void onMessage(M message, boolean isLeader, boolean hasLeader);
}