AssetBucket<D>: groupAssetssubgroupTypes onGet?: ()=>void | undefined assets: Map<string, Asset> waiters: KEventHandler<any> errorWaiters: KEventHandler<any> lastUID: number add(name: string | null , loader: Promise ): Asset<D> addLoaded(name: string | null , data: D ): Asset<D> get(handle: string ): Asset | undefined progress(): number getFailedAssets(): [ string, Asset ] [] waitFor(name: string , timeout: number ): PromiseLike<D>