@Override
  public List<? extends DataNodeId> getAllDataNodeIds() {
    // TODO: return all VCR nodes for recovery.
    return Collections.singletonList(currentDataNode);
  }
Remove {@link PartitionId} from assignedPartitionIds set, if {@param partitionIdStr} valid.
Used in one of the vcr state model classes {@link OnlineOfflineHelixVcrStateModel} or
{@link LeaderStandbyHelixVcrStateModel} if current VCR becomes offline for a partition.
@param partitionIdStr The partitionIdStr notified by Helix.
ambry-cloud/src/main/java/com/github/ambry/cloud/HelixVcrClusterParticipant.java