code: @Override
    public RemoteImageManifest getImageManifest(long fromTxnId)
        throws IOException {
      QuorumCall<AsyncLogger, RemoteImageManifest> q = loggers
          .getImageManifest(fromTxnId);
      Map<AsyncLogger, RemoteImageManifest> resps = loggers
          .waitForReadQuorumWithAllResponses(q, getImageManifestTimeoutMs,
              "getImageManifest");
      return createImageManifest(resps.values());
    }
docs: Get manifest for the images stored in journal nodes. An image is considered
  valid if it appears in majority of the nodes, with a valid md5 sum. The
  returned images are sorted according to their transaction id.