/// <reference types="node" />
import { Transform, Readable, TransformCallback } from "stream";
export declare class SSE extends Transform {
    constructor(opts?: any);
    _transform(chunk: any, encoding: string, cb: TransformCallback): void;
}
export declare class MessageBroker {
    messages: string[];
    private retry;
    private buffer;
    private defaultId;
    constructor(defaultRetry?: number);
    setRetry(num: number): void;
    setEventId(eventId?: number): void;
    resetEventId(): void;
    increaseId(): void;
    addMessage(event: string, obj: any, flush?: boolean): void;
    flushBuffer(): void;
    joinBuffer(): string;
    pop(): string;
    heartbeat(comment?: string): string | undefined;
    exitMessage(): boolean;
}
export declare class Subscription extends Readable {
    value: number;
    constructor(opts?: any);
    _read(): void;
}