import { Request, Response } from 'express';
export declare class Sse {
    private options;
    private eventEmitter;
    private activeListenerCount;
    constructor(options?: {
        keepAlive?: boolean;
        keepAliveDelay?: number;
        getInitialEvents?: (request: Request) => any[];
    });
    requestListener: (request: Request, response: Response) => void;
    send(data: any): void;
    close(): void;
}