What is going on with this one?

The line is too long, and instead of switching on the class, ask the class if it has DOI services.

```ruby
Curate.configuration.registered_curation_concern_types.each do |curation_concern_class_name|
  if  Hydra::RemoteIdentifier.registered?(:doi, curation_concern_class_name.constantize)
  ...
  end
end
```