OZG-7615 extract method in RootModelAssembler

src/main/java/de/ozgcloud/admin/RootModelAssembler.java

@@ -48,10 +48,14 @@ public class RootModelAssembler implements RepresentationModelAssembler<Root, En
 	@Override
 	public EntityModel<Root> toModel(Root root) {
 		var rootModel = EntityModel.of(root);
+		addLinks(rootModel);
+		return rootModel;
+	}
+
+	private void addLinks(EntityModel<Root> rootModel) {
 		rootModel.add(WebMvcLinkBuilder.linkTo(RootController.class).withSelfRel());
 		rootModel.addIf(currentUserService.hasConfigurationPermission(), this::buildConfigLink);
 		rootModel.addIf(Objects.nonNull(documentationProperties.getUrl()), () -> Link.of(documentationProperties.getUrl(), REL_DOCUMENTATIONS));
-		return rootModel;
 	}
 
 	private Link buildConfigLink() {