@Override
  public String getPartitionClass() {
    return partitionClass;
  }
Resolve the partition's status based on its replica's statuses.
If any one replica of a partition is {@link ReplicaSealStatus#SEALED}, then the partition is READ_ONLY.
If all the replicas are {@link ReplicaSealStatus#NOT_SEALED}, then the partition is READ_WRITE.
Otherwise, the partition is PARTIAL_READ_WRITE.
ambry-test-utils/src/main/java/com/github/ambry/clustermap/MockPartitionId.java