/// <reference types="node" />
import { Socket } from "net";
/**
 * Gracefully abort a WebSocket handshake.
 */
export declare function abortHandshake(socket: Socket, code: number, message?: string, headers?: Record<string, string>): void;
/**
 * Parses a `Sec-WebSocket-Protocol` header value.
 */
export declare function parseSubprotocols(header: string): Set<string>;
/**
 * Validates if a status code is allowed in a WebSocket close frame.
 */
export declare function isValidStatusCode(code: number): boolean;