class DataTable {

    public String getPagesAsString() {
        StringBuilder sb = new StringBuilder();
        if (this.pageNumbers.size() > 1) {
            sb.append("Pages ");
            
            if(pageNumbers.size() > 2 && hasConsecutivePages()) {
                sb.append(pageNumbers.first()).append("-").append(pageNumbers.last());
                return sb.toString();
            }
            
            int i = 0;
            for (Integer pageNumber : pageNumbers) {
                if (i != 0) {
                    sb.append(", ");
                }
                sb.append(pageNumber);
                i++;
            }
        } else {
            sb.append("Page ").append(pageNumbers.iterator().next());
        }

        return sb.toString();
    }

    public  DataTable(int pageNumber);
    public  DataTable(Collection<Integer> pageNumbers);

}