ranker = new StructuredQueryRanker(conf.get(Constants.IndexPath), fs, 1000);
mapping = ranker.getDocnoMapping();
queries = parseQueries(conf.get(Constants.QueriesPath), fs);
if (generator == null) {
if (conf.get(Constants.QueryType).equals(Constants.CLIR)) {
generator = new ProbabilisticStructuredQueryGenerator();
}else if (conf.get(Constants.QueryType).equals(Constants.MTN)) {
grammarPaths = parseGrammarPaths(conf.get(Constants.QueriesPath), fs);
generator = new MtNQueryGenerator();
}else {
generator = new BagOfWordsQueryGenerator();