private void populateReplicaList(int replicaCount, ReplicaState replicaState) {
    for (int i = 0; i < replicaCount; i++) {
      ReplicaId replicaId = new MockReplicaId(PORT, mockPartition, datanodes.get(i % datanodes.size()), 0);
      mockPartition.replicaIds.add(replicaId);
      mockPartition.replicaAndState.put(replicaId, replicaState);
    }
  }
Populate replicas for a partition.
@param replicaCount The number of replicas to populate.
@param replicaState The {@link ReplicaState} associated with these replicas.
ambry-router/src/test/java/com/github/ambry/router/UndeleteOperationTrackerTest.java