@Before
  public void setUp() throws Exception {
    fs = TEST_UTIL.getDFSCluster().getFileSystem();
    dir = new Path(TEST_UTIL.createRootDir(), currentTest.getMethodName());
    wals = new WALFactory(TEST_UTIL.getConfiguration(), currentTest.getMethodName());
  }
WAL tests that can be reused across providers.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/AbstractTestProtobufLog.java