import { BehaviorSubject } from 'rxjs';
export declare class SustainContext {
    subject: BehaviorSubject<{}>;
    constructor();
    context: any;
    set(key: string, value: any): void;
    sub(): BehaviorSubject<{}>;
    get(key: string): any;
    on(key: string): import("rxjs").Observable<any>;
}
export declare function getContext(): SustainContext;