if(!at.getSentences().hasNext()) { //no sentences  ... use this engine to detect
            //first the sentences
            TokenStream sentences = new SentenceTokenizer(new CharSequenceReader(at.getText()));
            try {
                while(sentences.incrementToken()){
                    OffsetAttribute offset = sentences.addAttribute(OffsetAttribute.class);
                    Sentence s = at.addSentence(offset.startOffset(), offset.endOffset());
                    if(log.isTraceEnabled()) {
                        log.trace("detected {}:{}",s,s.getSpan());
                    }
                }