ajax-loader,ajax-loader.gif not showing

I apologize ahead of time if this is not really an issue. I can't seem to see the ajax-loader spinner at all in my pages or on http://kenwheeler.github.io/slick/. I have even tried throttling my connection speed.

Slick.js's css targets

.slick-loading .slick-list { background: #fff url("./ajax-loader.gif") center center no-repeat; }

but .slick-loading isn't applied to the top level html element, .slick-loading is applied only to the image that is being loaded.

I have also tried with the latest 1.3.13

Is slick.js supposed to add a .slick-loading class to the top level slider html element? If so, I must be missing it? Maybe the class isn't added so the spinner isn't appearing?