public static PartitionRequestInfo readFrom(DataInputStream stream, ClusterMap clusterMap) throws IOException {
    int blobCount = stream.readInt();
    ArrayList<BlobId> ids = new ArrayList<BlobId>(blobCount);
    PartitionId partitionId = null;
    while (blobCount > 0) {
      BlobId id = new BlobId(stream, clusterMap);
      if (partitionId == null) {
        partitionId = id.getPartition();
      }
      ids.add(id);
      blobCount--;
    }
    return new PartitionRequestInfo(partitionId, ids);
  }
Contains the partition and the blob ids requested from a partition. This is used
by get request to specify the blob ids in a partition
ambry-protocol/src/main/java/com/github/ambry/protocol/PartitionRequestInfo.java