import { BalBreakpointObserver, BalBreakpoints } from './breakpoints.interfaces';
import { Subject } from '../types/signal';
export declare class BalBreakpointSubject extends Subject<BalBreakpointObserver> {
    private state;
    private listener;
    private debouncedNotify;
    constructor();
    attach(observer: BalBreakpointObserver): void;
    isEqual(newState: BalBreakpoints): boolean;
}
export declare const balBreakpointSubject: BalBreakpointSubject;
