/// <reference types="react" />
export declare let isObject: (obj: any) => boolean;
export declare let isArray: (arr: any) => boolean;
export declare function contains(root: any, n: any): boolean;
export declare function addEventListener(target: any, eventType: any, cb: any, option?: {}): {
    remove: () => void;
};
export declare function portal(container: any, children: any): {
    add(): import("react").ReactPortal;
    remove(): void;
};