require('dotenv').config(); module.exports = class MongoSingleton { static instance; constructor() { if (MongoSingleton.instance) return this.instance; MongoSingleton.instance = this; } static getInstance() { if (!MongoSingleton.instance) MongoSingleton.instance = new MongoSingleton(); return MongoSingleton.instance; } setup() { } start() { } stop() { } query() { } }