public static List<String> normalize(String line) throws IOException {
        List<String> normalwords = new ArrayList<String>();
        line = line.toLowerCase();
        CharArraySet set = RussianAnalyzer.getDefaultStopSet();
        RussianLuceneMorphology luceneMorph = new RussianLuceneMorphology();
        String words[] = line.split(" ");
         for (int i=0;i<words.length;i++) {
            String w =  words[i].replaceAll("[^а-я]", "");
            if (!w.equals("")) {
                List<String> wordNormalForms = luceneMorph.getNormalForms(w);
                String normalWord = wordNormalForms.get(0);
                if (!set.contains(normalWord)) {
                    normalwords.add(normalWord);
                }
            }
         }
        return normalwords;
       }