queryable_variables_get()

It currently returns an empty string. I've been contemplating adding a feature similar to drupal's return value where you enter the type of value you want it to return when nothing is found, but I've never had any use for that feature at all and cant think of any uses for it. It would be simple to add but would also add to the amount of arguments of the get/set functions. There are already 3 arguments for the Get function, and 4 for the set function. But I dont think I would make it a required field like drupal's get does. Drupal makes it an optional field but only for D7.