public Path getDataTestDirOnTestFS() throws IOException {
    if (dataTestDirOnTestFS == null) {
      setupDataTestDirOnTestFS();
    }

    return dataTestDirOnTestFS;
  }
Returns a Path in the test filesystem, obtained from {@link #getTestFileSystem()} to write
temporary test data. Call this method after setting up the mini dfs cluster if the test relies
on it.
@return a unique path in the test filesystem
hbase-testing-util/src/main/java/org/apache/hadoop/hbase/HBaseTestingUtility.java