@Override
  public Collection<? extends PartitionId> getAssignedPartitionIds() {
    return Collections.unmodifiableCollection(assignedPartitionIds);
  }
Construct the static VCR cluster.
@param cloudConfig The cloud configuration to use.
@param clusterMapConfig The clustermap configuration to use.
@param clusterMap The clustermap to use.
ambry-cloud/src/main/java/com/github/ambry/cloud/StaticVcrClusterParticipant.java