private void setupDataTestDirOnTestFS() throws IOException {
    if (dataTestDirOnTestFS != null) {
      LOG.warn("Data test on test fs dir already setup in " + dataTestDirOnTestFS.toString());
      return;
    }
    dataTestDirOnTestFS = getNewDataTestDirOnTestFS();
  }
Sets up a path in test filesystem to be used by tests. Creates a new directory if not already
setup.
hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtil.java