const db_url = process.env.NODE_ENV === 'TEST' ? mongo_address + process.env.MONGO_DB_TEST : mongo_address + process.env.MONGO_DB_PROD;
const db_url = process.env.NODE_ENV === 'TEST' ? mongo_address + process.env.MONGO_DB_TEST : mongo_address + process.env.MONGO_DB_PROD;