credentials->insert(std::pair<std::string, std::string>("username", username_));

credentials->insert(std::pair<std::string, std::string>("password", password_));

std::string token;

token.reserve(username_.size() + password_.size() + 2);

token.push_back(0);

token.append(username_);

token.push_back(0);

token.append(password_);

return token;