Hey @garthwebb I'm a bit confused, you correctly said:

> If we type hint $param, all existing code calling this method with
> 'null' (which is why the original code was casting) will fail, when they used to work properly.

This is what would happen with **this changeset** as well, a call like `$app->sendRequest(null, null, null, false)` will brake as far as I can see throwing a fatal at line 584, so this code doesn't pass the code review from my point of view.

Anyhow, there seems to be only two calls to `sendRequest` passing "params" as null since is a special case meant for forwarding the dispatched call:
* WikiaApp.class.php, line 714
* wikia.php, line 48