How to declare mongodb collection with JSDoc

Currently I am using WebStorm and hove something like

class MyClass {
  constructor(DB) {
    this.DB = DB;
  }
  doSomething() {
    await this.DB.findOne(...);
  }
} 

After I connect the MongoClient from the mongodb driver, I use the collection into a MyClass instance:

const actions = new MyClass(client.db(mainDB).collection(mainDBCollection));

client is response of mongodb.MongoClient.connect()

The WebStrom shows a notification:

Unresolved function or method `insertOne()` in the doSomething function of MyClass

How to declare in JSDoc that the DB in MyClass is a instance of the collection() function which I get from the mongodb client, so that WebStorm can recognize the functions used in the this.DB/mongo collection?