import { LitElement } from 'lit'; export type UnpackCustomEvent = T extends CustomEvent ? U : never; export declare class EventEmitterBase extends LitElement { addEventListener(type: K, listener: (this: HTMLElement, ev: M[K]) => any, options?: boolean | AddEventListenerOptions): void; removeEventListener(type: K, listener: (this: HTMLElement, ev: M[K]) => any, options?: boolean | EventListenerOptions): void; emitEvent>(type: K, eventInitDict?: CustomEventInit): boolean; }