public List<ReplicaTracker> getPreAssignedReplicas(List<ReplicaStatus> statuses) {
    return preAssignedReplicas.stream()
        .filter(replicaTracker -> statuses.contains(replicaTracker.getReplicaStatus()))
        .collect(Collectors.toList());
  }
This class tracks for a current state for Active groups for a continuous replication cycle.
Active group tracker have preassigned replicas and from these replicas only we create active remote replica groups
Any remote replica group created for this tracker has replicas with ACTIVE state only
ambry-replication/src/main/java/com/github/ambry/replication/continuous/ActiveGroupTracker.java