That line looks like complete gibberish to me. If my task is to fix a bug in the sorted table, I expect to find a list of somekind (the data source) and a (set

That line looks like complete gibberish to me. If my task is to fix a bug in the sorted table, I expect to find a list of somekind (the data source) and a (set of) sorting functions that can sort the data set. Not a magical #id ref and mysterious method call.