Can't mock error response after an example is chosen

[lehphyro]

Describe the bug
Prefer: code=400 doesn't work after a request with Prefer: example=elon is sent.
It works if no example has been chosen previously.

To Reproduce

1. Given the attached OpenAPI document
2. Run this CLI command: prism mock openapi.yaml -h 0.0.0.0
3. Execute the following requests:

curl -H "Prefer: example=elon" http://localhost:14080/client-api/v2/test
curl -H "Prefer: code=400" http://localhost:14080/client-api/v2/test

Expected behavior
I expect a 400 error response in the second request, I get the same response as the first request instead.

Additional context
Might be related to #1071
openapi.txt

[XVincentX]

Can you try this branch? #1074

[lehphyro]

That fixes the issue 👍

[lehphyro]

@XVincentX that's was quick :) Maybe you can help fix this issue in spectral that's been open for a while? stoplightio/spectral#870

[XVincentX]

@lehphyro Tengo dos manos solo :)