import { EventsKey } from './events';
import BaseEvent from './events/Event';
import Target from './events/Target';

export default class Observable extends Target {
    constructor();
    changed(): void;
    getRevision(): number;
    on(type: string | string[], listener: (p0: any) => any): EventsKey | EventsKey[];
    once(type: string | string[], listener: (p0: any) => any): EventsKey | EventsKey[];
    un(type: string | string[], listener: (p0: any) => any): void;
    on(type: 'change', listener: (evt: BaseEvent) => void): EventsKey;
    once(type: 'change', listener: (evt: BaseEvent) => void): EventsKey;
    un(type: 'change', listener: (evt: BaseEvent) => void): void;
    on(type: 'error', listener: (evt: BaseEvent) => void): EventsKey;
    once(type: 'error', listener: (evt: BaseEvent) => void): EventsKey;
    un(type: 'error', listener: (evt: BaseEvent) => void): void;
}
export function unByKey(key: EventsKey | EventsKey[]): void;