`int`? I think it's a reserved keyword, but what did you mean it to mean? Initialize?

Yes, I think it should all be encapsulated into something like
````
if (req && apiMock.shouldMock(req))
  apiMock.mockRequest(req);
````

This makes me think of how Factory and things work. I'm thinking that someone can write their own apiMock and use that instead of the default. But then again, the "magic" is just adding a `httpInterceptor` and is 2 lines of code so then this library wouldn't be needed.