docs: private String getCamelCaseFromUnderscoreSeparated(String underScoreSeparatedStr) {
  
      final StringGrabber underScoreSeparatedSg = new StringGrabber(underScoreSeparatedStr);
      final StringGrabberList wordBlockList = underScoreSeparatedSg.split("_");
      final StringGrabber resultSg = new StringGrabber();
  
      for (int i = 0; i < wordBlockList.size(); i++) {
  
        final StringGrabber word = wordBlockList.get(i);
  
        if (i == 0) {
  
          // first element not to upper case
          resultSg.append(word.toString());
  
        } else {
          resultSg.append(word.replaceFirstToUpperCase().toString());
        }
      }
      return resultSg.toString();
    }