docs: public static boolean checkOffsets(CoreMap docAnnotation)
    {
      boolean okay = true;
      String docText = docAnnotation.get(CoreAnnotations.TextAnnotation.class);
      String docId = docAnnotation.get(CoreAnnotations.DocIDAnnotation.class);
      List<CoreLabel> docTokens = docAnnotation.get(CoreAnnotations.TokensAnnotation.class);
      List<CoreMap> sentences = docAnnotation.get(CoreAnnotations.SentencesAnnotation.class);
      for (CoreMap sentence:sentences) {
        String sentText = sentence.get(CoreAnnotations.TextAnnotation.class);
        List<CoreLabel> sentTokens = sentence.get(CoreAnnotations.TokensAnnotation.class);
        int sentBeginChar = sentence.get(CoreAnnotations.CharacterOffsetBeginAnnotation.class);
        int sentEndChar = sentence.get(CoreAnnotations.CharacterOffsetEndAnnotation.class);
        int sentBeginToken = sentence.get(CoreAnnotations.TokenBeginAnnotation.class);
        int sentEndToken = sentence.get(CoreAnnotations.TokenEndAnnotation.class);
        String docTextSpan = docText.substring(sentBeginChar, sentEndChar);
        List<CoreLabel> docTokenSpan = new ArrayList<CoreLabel>(docTokens.subList(sentBeginToken, sentEndToken));
        logger.finer("Checking Document " + docId + " span (" + sentBeginChar + "," + sentEndChar + ") ");
        if (!docTextSpan.equals(sentText) ) {
          okay = false;
          logger.finer("WARNING: Document " + docId + " span does not match sentence");
          logger.finer("DocSpanText: " + docTextSpan);
          logger.finer("SentenceText: " + sentText);
        }
        String sentTokenStr = getTokenText(sentTokens, CoreAnnotations.TextAnnotation.class);
        String docTokenStr = getTokenText(docTokenSpan, CoreAnnotations.TextAnnotation.class);
        if (!docTokenStr.equals(sentTokenStr) ) {
          okay = false;
          logger.finer("WARNING: Document " + docId + " tokens does not match sentence");
          logger.finer("DocSpanTokens: " + docTokenStr);
          logger.finer("SentenceTokens: " + sentTokenStr);
        }
      }
      return okay;
    }