private final Collection<String> getHFiles(Path dir, FileSystem fs, TableName tableName)
    throws IOException {
    Path tableDir = CommonFSUtils.getTableDir(dir, tableName);
    return SnapshotTestingUtils.listHFileNames(fs, tableDir);
  }
@return all the HFiles for a given table in the specified dir
@throws IOException on expected failure
hbase-server/src/test/java/org/apache/hadoop/hbase/master/cleaner/TestSnapshotFromMaster.java