Map<String, Map<String, String>> getPartitionStateMapForInstance(String instanceName) {
    ReplicaStateInfos replicaStateInfos = instanceToReplicaStateInfos.get(instanceName);
    return replicaStateInfos != null ? replicaStateInfos.getReplicaStateMap() : new HashMap<>();
  }
Get states of all partitions that reside on given instance.
@param instanceName the name of instance where partitions reside
@return a map representing states of partitions from given instance.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/MockHelixAdmin.java