if !c.Exists(collections.Gateway, resource.NewName(r.Metadata.FullName.Namespace, gwName)) {
            // Messages are defined in galley/pkg/config/analysis/msg/messages.yaml
            // From there, code is generated for each message type, including a constructor function
            // that you can use to create a new validation message of each type.
            msg := msg.NewReferencedResourceNotFound(r, "gateway", gwName)