28/ An Embedded Stub is production code that stubs out your third-party infrastructure library.
It's not a stub of your code; it's a stub of the standard library, or framework, or what have you.
For example, in Node, you use `http.request()` to make an HTTP request. The Embedded Stub stubs out `http`. The stub is used when `createNull()` is called, and the normal `http` is used when `create()` is called.
As a result, *all your code* runs the same regardless of whether it's Nulled or not.