How to use the kinvey-nativescript-sdk.DataStore.collection function in kinvey-nativescript-sdk

];

export class CarService {
    static getInstance(): CarService {
        return CarService._instance;
    }

    private static _instance: CarService = new CarService();

    private static cloneUpdateModel(car: Car): object {
        // tslint:disable-next-line:ban-comma-operator
        return editableProperties.reduce((a, e) => (a[e] = car[e], a), { _id: car.id });
    }

    private allCars: Array = [];
    private carsStore = DataStore.collection("cars");

    constructor() {
        if (CarService._instance) {
            throw new Error("Use CarService.getInstance() instead of new.");
        }

        CarService._instance = this;
    }

    load(): Promise {
        return this.login().then(() => {
            return this.carsStore.sync();
        }).then(() => {
            const sortByNameQuery = new Query();
            sortByNameQuery.ascending("name");
            const stream = this.carsStore.find(sortByNameQuery);