How can I close the client-side JavaScript 'Hub' connection in SignalR?

I have followed this tutorial.

But there is no hint how to close the Websocket connection via the HubConnection class in signalr.js-file. The file is V1.0.4.

This solution does not resolve my problem because I am using the microsofts javascript-library.

Here ist the code:

var lHubConnection = null;

var Init = function () {

    // create instance
    lHubConnection = new signalR.lHubConnectionBuilder().withUrl("/chatHub").build();

    // receive message
    lHubConnection.on("ReceiveMessage", function (pMessage) {

        // show message
        console.log(JSON.parse(pMessage));
    });

    // [...]
};

// close websocket connection
var CloseConnection = function(){

    if (lHubConnection !== null && lHubConnection.connection.connectionState === 1) {   
        // lHubConnection.invoke("?"); ???
    }
};

Here is an console output of the lHubConnection instance: