How to terminate futureUserData | Stop the keep alive setTimeout?

[doppelgunner]

   let wsEndpoint = null;
   client.userFutureData(null,null,
        data => {
            console.log('data', data);
        },
        endpoint => {
            wsEndpoint = endpoint
        }
    )

    setTimeout(() => {
       client.futuresTerminate(wsEndpoint)
    }, 3000)

But it's still running because of the setTimeout(). I want to be able to stop it fully after terminating the websocket. Also, if the websocket is not yet terminated... then keep the keepalive open... how to achieve this?