constructor() {
        this.events = new EventEmitter();
        this.total = 0;
        this.loaded = 0;
        this.progress = 0;
        this.path = '';
        this.crossOrigin = 'anonymous';
        this.fetchOptions;
        this.cache = false;
        this.files = {};
        this.promise = new Promise(resolve => this.resolve = resolve);
    }
@author pschroen / https://ufo.ai/

Based on https://github.com/mrdoob/three.js/blob/dev/src/loaders/Cache.js
Based on https://github.com/mrdoob/three.js/blob/dev/src/loaders/Loader.js