import { ExtensionDefinition, ExtensionStateFromDefinition } from './definition';
import { StateSubscriberOpts } from '../interfaces';
import { Reka } from '../reka';
export declare class Extension<D extends ExtensionDefinition = any> {
    reka: Reka;
    definition: D;
    state: ExtensionStateFromDefinition<D>;
    constructor(reka: Reka, definition: D);
    init(): void;
    dispose(): void;
    subscribe<C extends Record<string, any>>(collector: (state: D['state']) => C, subscriber: (collected: C, prevCollected: C | undefined) => void, opts?: StateSubscriberOpts): () => void;
}