protected void deleteTestDir(FileSystem fs) throws IOException {
    Path dataTestDir = TEST_UTIL.getDataTestDir();
    if (fs.exists(dataTestDir)) {
      fs.delete(dataTestDir, true);
    }
  }
Test that we only count block size once per block while scanning
hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestHFileReaderImpl.java