code: private List<Integer> getNodeIdListForPartitionIdList(List<Integer> partitionIds)
              throws VoldemortException {
          List<Integer> nodeIds = new ArrayList<Integer>(partitionIds.size());
          for(Integer partitionId: partitionIds) {
              int nodeId = getNodeIdForPartitionId(partitionId);
              if(nodeIds.contains(nodeId)) {
                  throw new VoldemortException("Node ID " + nodeId + " already in list of Node IDs.");
              } else {
                  nodeIds.add(nodeId);
              }
          }
          return nodeIds;
      }
docs: Converts from partitionId to nodeId. The list of partition IDs,
  partitionIds, is expected to be a "replicating partition list", i.e., the
  mapping from partition ID to node ID should be one to one.
  
  @param partitionIds List of partition IDs for which to find the Node ID
  for the Node that owns the partition.
  @return List of node ids, one for each partition ID in partitionIds
  @throws VoldemortException If multiple partition IDs in partitionIds map
  to the same Node ID.