static void assertGet(final HRegion r, final byte[] family, final byte[] k) throws IOException {
    // Now I have k, get values out and assert they are as expected.
    Get get = new Get(k).addFamily(family).readAllVersions();
    Cell[] results = r.get(get).rawCells();
    for (int j = 0; j < results.length; j++) {
      byte[] tmp = CellUtil.cloneValue(results[j]);
      // Row should be equal to value every time.
      assertTrue(Bytes.equals(k, tmp));
    }
  }
For this test,the spied {@link AsyncFSWAL} can not work properly because of a Mockito defect
that can not deal with classes which have a field of an inner class. See discussions in
HBASE-15536.When we reuse the code of {@link AsyncFSWAL} for {@link FSHLog}, this test could
not work for {@link FSHLog} also.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHRegion.java