import { AddEventListeners, EventType, IBroadcastChannel, Method, MethodType, Options as BroadcastChannelOptions } from "./types";
export declare function enforceOptions(options: BroadcastChannelOptions): void;
/**
 * Contains all open channels,
 * used in tests to ensure everything is closed.
 */
export declare const OPEN_BROADCAST_CHANNELS: Set<BroadcastChannel<unknown>>;
export declare class BroadcastChannel<T = any> implements IBroadcastChannel<T> {
    static _pubkey: boolean;
    id: number;
    name: string;
    options: BroadcastChannelOptions;
    method: Method;
    closed: boolean;
    _addEL: AddEventListeners;
    _prepP: Promise<unknown> | null;
    _state: unknown;
    _uMP: Set<Promise<T>>;
    _iL: boolean;
    private _onML;
    private _befC;
    constructor(name: string, options?: BroadcastChannelOptions);
    get type(): MethodType;
    get isClosed(): boolean;
    set onmessage(fn: ((data: T) => void) | null);
    postMessage(msg: T): Promise<T>;
    postInternal(msg: unknown): Promise<unknown>;
    addEventListener(type: EventType, fn: (data: T) => void): void;
    removeEventListener(type: EventType, fn: (data: T) => void): void;
    close(): Promise<void>;
}