public void restoreSnapshots(Configuration conf, Map<String, Path> snapshotToDir, FileSystem fs)
    throws IOException {
    // TODO: restore from record readers to parallelize.
    Path rootDir = CommonFSUtils.getRootDir(conf);

    for (Map.Entry<String, Path> entry : snapshotToDir.entrySet()) {
      String snapshotName = entry.getKey();
      Path restoreDir = entry.getValue();
      LOG.info("Restoring snapshot " + snapshotName + " into " + restoreDir
        + " for MultiTableSnapshotInputFormat");
      restoreSnapshot(conf, snapshotName, rootDir, restoreDir, fs);
    }
  }
Restore each (snapshot name, restore directory) pair in snapshotToDir
@param conf          configuration to restore with
@param snapshotToDir mapping from snapshot names to restore directories
@param fs            filesystem to do snapshot restoration on
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/MultiTableSnapshotInputFormatImpl.java