code: private Path getFileForLockFile(Path lockFile, Path sourceDirPath)
            throws IOException {
      String lockFileName = lockFile.getName();
      Path dataFile = new Path(sourceDirPath + Path.SEPARATOR + lockFileName + inprogress_suffix);
      if( hdfs.exists(dataFile) ) {
        return dataFile;
      }
      dataFile = new Path(sourceDirPath + Path.SEPARATOR +  lockFileName);
      if(hdfs.exists(dataFile)) {
        return dataFile;
      }
      return null;
    }
docs: Returns the corresponding input file in the 'sourceDirPath' for the specified lock file.
  If no such file is found then returns null