There's little point to check having at least one

argument at all. Feedback:
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1942#note_30495480

lib/api/groups.rb

@@ -119,8 +119,6 @@ module API
         optional :name, type: String, desc: 'The name of the group'
         optional :path, type: String, desc: 'The path of the group'
         use :optional_params
-
-        at_least_one_of(*@declared_params.flatten - [:id])
       end
       put ':id' do
         group = find_group!(params[:id])

lib/api/users.rb

@@ -140,8 +140,6 @@ module API
         optional :name, type: String, desc: 'The name of the user'
         optional :username, type: String, desc: 'The username of the user'
         use :optional_attributes
-
-        at_least_one_of(*@declared_params.flatten - [:id])
       end
       put ":id" do
         authenticated_as_admin!

spec/requests/api/users_spec.rb

@@ -431,7 +431,7 @@ describe API::Users do
       expect(response).to have_http_status(200)
       expect(json_response['shared_runners_minutes_limit'])
         .to eq(133)
-      expect(user.reload.namespace.shared_runners_minutes_limit).to eq(133)
+      expect(user.reload.shared_runners_minutes_limit).to eq(133)
     end
 
     it "does not update admin status" do