private boolean isRecordsValid(ArrayList<ArrayList<String>> records,
                                      int columnNumber) {
        
        if (records == null || columnNumber < 1) {
            return false;
        }
        if (records.isEmpty()) {
            return false;
        }
        else {
            for (ArrayList<String> record : records) {
                if (record.size() != columnNumber) {
                    return false;
                }
            }
        }
        return true;
        
    }