try {
LayeredTokenMatcher m = pattern.matcher(sentence);
Collection<ChunkedExtraction> results = new ArrayList<ChunkedExtraction>();
while (m.find()) {
int start = m.start();
int length = m.end() - start;
Range r = new Range(start, length);
ChunkedExtraction extr = new ChunkedExtraction(sentence, r);
results.add(extr);