public List<ReplicaThread.RemoteReplicaGroup> processFinishedGroups() {
    List<ReplicaThread.RemoteReplicaGroup> finishedGroups = new ArrayList<>();
    getGroupTrackers().forEach(groupTracker -> {
      if (!groupTracker.isGroupDone()) {
        return;
      }
      finishedGroups.add(groupTracker.getRemoteReplicaGroup());
      groupTracker.finishIteration();
    });
    return finishedGroups;
  }
Iterates over all group trackers and if remote replica group is getting tracked by group tracker is done,
removes it from group tracker
@return returns list of remote replica groups removed from tracking
ambry-replication/src/main/java/com/github/ambry/replication/continuous/DataNodeTracker.java