throws IOException {
SavedStreams streams = (SavedStreams) getPreviousTokenStream();
if (streams == null) {
streams = new SavedStreams();
setPreviousTokenStream(streams);
streams.tokenStream = new SentenceTokenizer(reader);
streams.filteredTokenStream = new WordTokenFilter(streams.tokenStream);
streams.filteredTokenStream = new PorterStemFilter(streams.filteredTokenStream);
if (!stopWords.isEmpty()) {
streams.filteredTokenStream = new StopFilter(matchVersion, streams.filteredTokenStream, stopWords, false);
}