constructor() {
    /**
     * @type {!Object<string, import("./IconImage.js").default>}
     * @private
     */
    this.cache_ = {};

    /**
     * @type {!Object<string, CanvasPattern>}
     * @private
     */
    this.patternCache_ = {};

    /**
     * @type {number}
     * @private
     */
    this.cacheSize_ = 0;

    /**
     * @type {number}
     * @private
     */
    this.maxCacheSize_ = 1024;
  }
@classdesc
Singleton class. Available through {@link module:ol/style/IconImageCache.shared}.