code: private void fixBCFSplits(
  			List<FileSplit> splits, List<InputSplit> newSplits)
  		throws IOException
  	{
  		// addGuessedSplits() requires the given splits to be sorted by file
  		// path, so do so. Although FileInputFormat.getSplits() does, at the time
  		// of writing this, generate them in that order, we shouldn't rely on it.
  		Collections.sort(splits, new Comparator<FileSplit>() {
  			public int compare(FileSplit a, FileSplit b) {
  				return a.getPath().compareTo(b.getPath());
  			}
  		});
  
  		for (int i = 0; i < splits.size();)
  			i = addGuessedSplits(splits, i, newSplits);
  	}
docs: FileVirtualSplits, uncompressed in FileSplits.