std::vector<bsoncxx::document::value> documents;
            for(int i = 0; i < 100; i++) {
                documents.push_back(
                        bsoncxx::builder::stream::document{} << "i" << i << finalize);
            }
            auto result  = collection.insert_many(documents);
            if(result) {
                auto ids = result.value().inserted_ids();
                for (auto it = ids.begin(); it != ids.end(); ++it) {
                    //cout << it->second.get_oid().value.to_string() << endl;
                    auto second = it->second;
                    auto oId = second.get_oid();
                    auto idValue = oId.value;
                    string str = idValue.to_string();
                }
            }