export interface IEvent<T> {
    on(key: string, handler: {
        (data?: T): void;
    }): void;
    off(key: string): void;
}
export declare class Event<T> implements IEvent<T> {
    handlers: {
        (data?: T): void;
    }[];
    keyDict: {};
    single(handler: {
        (data?: T): void;
    }): void;
    on(key: string, handler: {
        (data?: T): void;
    }): void;
    off(key: string): void;
    trigger(data?: T): void;
    triggerSingelWithRet(data?: T): void;
}