getLayers() {
    return /** @type {!Collection<import("./Base.js").default>} */ (
      this.get(Property.LAYERS)
    );
  }
Returns the {@link module:ol/Collection~Collection collection} of {@link module:ol/layer/Layer~Layer layers}
in this group.
@return {!Collection<import("./Base.js").default>} Collection of
  {@link module:ol/layer/Base~BaseLayer layers} that are part of this group.
@observable
@api