import { Subject } from '../types/signal';
import { BalOrientationObserver } from './orientation.interfaces';
export declare class BalOrientationSubject extends Subject<BalOrientationObserver> {
    private listener;
    private state;
    constructor();
    attach(observer: BalOrientationObserver): void;
    private isEqual;
}
export declare const balOrientationSubject: BalOrientationSubject;
