How do I bring back my own jSON via post process?

I can't seem to change anything.

I want to process my result set and then create my own JSON response. No matter what I do it doesn't seem to affect the results.

For instance;

//****************** Post-processing script on the stored procedure ******************

var_dump(event.response); // outputs to file in storage/log of dreamfactory install directory

var lodash = require("lodash.min.js");

return ["stuff"];

This doesn't return "stuff" just the list of original records it is supposed to send. How do I intercept the result and then process it and return the new JSON.

Thanks