import * as i0 from "@angular/core";
export declare class PromiseQueue {
    private _runningPromise;
    constructor();
    queuePromise(fn: Function): Promise<void>;
    static ɵfac: i0.ɵɵFactoryDef<PromiseQueue, never>;
    static ɵprov: i0.ɵɵInjectableDef<PromiseQueue>;
}