@Override
  public int compareTo(PartitionId o) {
    AmbryPartition other = (AmbryPartition) o;
    return Long.compare(id, other.id);
  }
Instantiate an AmbryPartition instance.
@param id the id associated with this partition.
@param partitionClass the partition class that this partition belongs to
@param clusterManagerQueryHelper {@link HelixClusterManagerQueryHelper} to query cluster information.
ambry-clustermap/src/main/java/com/github/ambry/clustermap/AmbryPartition.java