import { EventBus } from '../utils/EventBus';
import { EventListener } from '../utils/EventListener';
import { Scalar } from './Scalar';
export declare class DiffBus<State, T extends Record<string, Scalar>> {
    private stateGetter;
    private state;
    private diffBus;
    constructor(stateBus: EventBus<State>, stateGetter: (state: State) => T);
    private _getDiff;
    subscribe(listener: EventListener<Partial<T>>): {
        unsubscribe: () => void;
    };
}