Write tests around API for domain lock

app/controllers/api/v1/registrant/base_controller.rb

@@ -22,6 +22,15 @@ module Api
           header.gsub(pattern, '') if header&.match(pattern)
         end
 
+        def associated_domains(user)
+          country_code, ident = user.registrant_ident.split('-')
+
+          BusinessRegistryCache.fetch_associated_domains(ident, country_code)
+        rescue Soap::Arireg::NotAvailableError => error
+          Rails.logger.fatal("[EXCEPTION] #{error}")
+          user.domains
+        end
+
         def authenticate
           decryptor = AuthTokenDecryptor.create_with_defaults(bearer_token)
           decryptor.decrypt_token