private String[] toStringArray(TableName[] list) {
    String[] arr = new String[list.length];
    for (int i = 0; i < list.length; i++) {
      arr[i] = list[i].toString();
    }
    return arr;
  }
Clean up the data at target directory
@throws IOException if cleaning up the backup directory fails
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/impl/BackupAdminImpl.java