void TextIndexMergerTestCase::printPositngAnswer(const TermMap& answer)
{
    for (TermMap::const_iterator it = answer.begin(); 
         it != answer.end(); ++it)
    {
        std::cout << "Anser term hash: " << it->first << std::endl;

        std::cout << "anser doc list: " << std::endl;
        for (size_t i = 0; i < it->second.size(); ++i)
        {
            std::cout << it->second[i].first << ", ";
        }
        std::cout << "end anser doc list: " << std::endl;

        ctf_t ctf = 0;
        std::cout << "anser tf list: " << std::endl;
        for (size_t i = 0; i < it->second.size(); ++i)
        {
            ctf += it->second[i].second.size();
            std::cout << it->second[i].second.size() << ", ";
        }
        std::cout << "end anser tf list: " << std::endl;

        std::cout << "anser pos list: " << std::endl;
        for (size_t i = 0; i < it->second.size(); ++i)
        {
            for (size_t j = 0; j < it->second[i].second.size(); ++j)
            {
                std::cout << it->second[i].second[j] << ", ";
            }
        }
        std::cout << "end anser pos list: " << std::endl;
        std::cout << "Anser term meta: df: " << it->second.size()
                  << ", ctf: " << ctf << std::endl;
    }
}