Function getThumbnailsArray is returning an empty NodeList

Hello. I’m having a strange bit of a problem. After using the debugger in Chrome (really firefox but I’m using both browsers) I’m seeing that the function getThumbnailsArray is returning an empty NodeList.

This obviously is a problem since it then creates an empty array, which cases the whole point of the chapter to be mute since none of the anchor tags have the required event handler, and clicking on a thumb simply opens up the source image.

The interesting part is that the internal code works just fine when entered in the console. Any suggestions?

I’m sad to admit I had single quotes around THUMBNAIL_LINK_SELECTOR variable. All is well.