Unclear about twitter config settings in index.js

[MemeRunner]

Regarding the code below, this would go in the index.js file for the function, correct?

And I presume the XXX's are where your authorization credentials go?

What I'm not clear on is, I thought the purpose of using twitter_config was to not have the authorization credentials visible in the index.js file.

For the XXX, do I leave them blank, like ""?

Appreciate any guidance on this.

    var config = {
    {
        "consumerKey": "XXX",
        "consumerSecret": "XXX",
        "accessToken": "XXX",
        "accessTokenSecret": "XXX",
        "callBackUrl": "XXX"
    }