int countRows(byte[] start, byte[] end) throws IOException {
    return TEST_UTIL.countRows(tbl, new Scan().withStartRow(start).withStopRow(end));
  }
Counts the number of rows to verify data loss or non-dataloss.
hbase-server/src/test/java/org/apache/hadoop/hbase/util/BaseTestHBaseFsck.java