Forgive me for being a ruby newbie, but there are some things I don't understand here ... I see that this is returning a string to the requestor that calls a `jsonCallback` function.  What is that?

In the `map` loop, what do the parameters `resource` and `instance` refer to?

And then, I'm not going to lie ... I have no idea what line 104 is doing.  Help me out?  :smile: