Type '{ name: string; readonly clients: Set<WebSocketClient>; close(): Promise<void>; on: { (event: "connection", cb: (this: Server<...>, socket: WebSocket, request: IncomingMessage) => void): Server<...>; (event: "error", cb: (this: Server<...>, error: Error) => void): Server<...>; (event: "headers", cb: (this: Server<.....' is not assignable to type 'WebSocketServer'.