Long getBlobContentCRC(MessageInfo msg, BlobStore store) {
    try {
      return store.getBlobContentCRC(msg);
    } catch (Throwable e) {
      metrics.backupCheckerRuntimeError.inc();
      String err = String.format("[BackupIntegrityMonitor] Failed to get CRC for blob %s due to",
          msg.getStoreKey().getID());
      logger.error(err, e);
    }
    return null;
  }
Returns CRC of blob-content
@param msg Metadata of blob
@param store Local blob store
@return CRC of blob-content
ambry-cloud/src/main/java/com/github/ambry/cloud/BackupIntegrityMonitor.java