When a static response is not enough, we can take the real data from server and modify it to our liking. This saves a ton of time, because we don’t need to create the data ourselves. Instead, we can take e.g. response body and change only a desired attribute. This gives us one more advantage, because we can first make assertions on real data, and only then make changes. This is a great advantage compared to providing a static response, that essentially creates a blind spot for any API changes.