BlockTokenSecretManager btsm = cluster.getNamesystem().getBlockManager()
.getBlockTokenSecretManager();
btsm.setKeyUpdateIntervalForTesting(2 * 1000);
btsm.setTokenLifetime(2 * 1000);
btsm.clearAllKeysForTesting();
fs = getFileSystem(conf);
assertEquals(PLAIN_TEXT, DFSTestUtil.readFile(fs, TEST_PATH));
assertEquals(checksum, fs.getFileChecksum(TEST_PATH));