Sorry, just noticed another thing: the URL methods we’ve got elsewhere in this library follow the convention of `thing_url(parameter)`, rather than `thing_url_for(parameter)`. Examples: [`ContentApi#artefact_url`](https://github.com/alphagov/gds-api-adapters/blob/0dfb416b859de34822954cbdf727121c0cfc16a1/lib/gds_api/content_api.rb#L151), [`Rummager#search_url`](https://github.com/alphagov/gds-api-adapters/blob/0dfb416b859de34822954cbdf727121c0cfc16a1/lib/gds_api/rummager.rb#L29).