export declare const keyPressEmitSystem: {
    add: ((item: Set<string>, initData?: void | Record<string, any> | undefined) => false | import("@lincode/promiselikes").Cancellable) | ((item: Set<string>, initData?: void | Record<string, any> | undefined) => boolean);
    delete: ((item: Set<string>) => false | import("@lincode/promiselikes").Cancellable | undefined) | ((item: Set<string>) => boolean);
};