@Override
      public void storeFile(final String region, final String family, final String hfileName)
        throws IOException {
        hfiles.add(hfileName);
      }
List all the HFiles in the given table
@param fs       FileSystem where the table lives
@param tableDir directory of the table
@return array of the current HFiles in the table (could be a zero-length array)
@throws IOException on unexecpted error reading the FS
hbase-server/src/test/java/org/apache/hadoop/hbase/snapshot/SnapshotTestingUtils.java