I have the strange behavior (as i think) of console.log. So, there is two console.log in my console, first shows PdfViewerApplication object, second shows it's fieid, named eventBus.
So, as you can see second line says that PdfViewerApplication.eventBus right?
Now lets look at first line (before! second) , expand the body of the object and find eventBus field.

Obviously it is not null there, it almost has 2 eventListeners (pagesloaded)!
How is it possible?