private BufferedWriter writer() throws IOException {
    Path exportToFile = new Path(exportRootDataDir, EximUtil.FILES_NAME);
    logger.debug("exporting data files in dir : " + dataPathList + " to " + exportToFile);
    return new BufferedWriter(
            new OutputStreamWriter(exportFileSystem.create(exportToFile))
    );
  }
This needs the root data directory to which the data needs to be exported to.
The data export here is a list of files either in table/partition that are written to the _files
in the exportRootDataDir provided.
ql/src/java/org/apache/hadoop/hive/ql/parse/repl/dump/io/FileOperations.java