error when response has no content type is very vague

[barbeque-squared]

Run npx apib2swagger -i blueprint.apib --open-api-3 on this apib:

FORMAT: 1A
HOST: http://example.org

# My Title

This is some blueprint

# Group A Group

## Some URL [/some/url]

### Some super awesome endpoint [PUT]
+ Request
  + Attributes (object)
+ Response 200
  + Attributes (object)

Expected result: not sure actually (see details)

Actual result:

TypeError: Cannot read properties of undefined (reading 'value')
    at setResponseSchema (.../node_modules/apib2swagger/src/responses.js:92:28)

Details:
I can make it work by either:

• changing the if to if (contentTypeHeader === undefined || !contentTypeHeader.value)
• Response 200 (application/json)

but I can't figure out whether

1. the response should always have a content type, or
2. the response does not necessarily need to have a content type

because on the one hand there's an if check that I think is just supposed to return if it doesn't have a content type? The API blueprint docs would also suggest that this is valid?

• https://apiblueprint.org/documentation/specification.html#request-section
• https://apiblueprint.org/documentation/specification.html#response-section
• https://apiblueprint.org/documentation/specification.html#payload-section

on the other I'm also fine with having to explicitly set them since it's not bad to do so, but in that case the error should be made clearer.