export declare class NgxHotkeyService {
    private hotkeys;
    private lastHotkeyFired;
    constructor();
    add(shortcut: string, callback: (event: KeyboardEvent) => boolean): void;
    remove(shortcut: string): void;
    private checkKeyDown;
    private onKeyUp;
    private checkHotKey;
    private isTheSameLastHotkeyFired;
}