Where does getItemProperty method/function come from?

I'm totally baffled on where this getItemProperty method is coming from. For example in the Text template it is used but I can't find it anywhere in the prototype hierarchy... Any hints? I notice that it's defined in the list template but I just am not seeing how it can be present in some of the other places I'm seeing it...

By the way, I'm just going through the code trying to understand how it all works because this is an absolutely phenomenal set of javascript! I think it would make a nice API for creating other widgets and I'd to use it but I'm trying to understand it first...

Any enlightenment is very welcome!

OK, I think I'm seeing it now... the Text template is only used from within a List template that handily adds that method to each text template it creates... hmm...