How to use mongodb-memory-server-core

/**
  * Stops the store
  *
  * @returns {Promise} Success or not?
  * @memberof Disk
  */
 async stop() {
  debug('stopping %s', this.name);

  await super.stop();

  await this.mongod.stop();
 }

// connect to in-memory mongodb Server
  // eslint-disable-next-line no-underscore-dangle
  mongoServer.getUri().then((mongoUri) => {
   mongoose.connect(mongoUri, mongoOptions);
   logger.debug('using mongo-memory-server');
  });

/**
  * Starts the store
  *
  * @returns {Promise} Resolves or not
  * @memberof Disk
  */
 async start() {
  debug('starting %s', this.name);

  const dataPath = path.join(
   os.tmpdir(),
   `henri-mongo-${md5(process.cwd())}`
  );

  if (!fs.existsSync(dataPath)) {
   fs.mkdirSync(dataPath);
  }

  this.mongod = new MongoMemoryServer({
   instance: {
    dbName: 'henri',
    dbPath: this.henri.isTest ? null : dataPath,
    storageEngine: this.henri.isTest ? 'ephemeralForTest' : 'wiredTiger',
   },
  });

  this.config.url = await this.mongod.getConnectionString();

  return super.start();
 }