Add the uniqueModel in DataModelRegistry::registerModel to be an

optional parameter

Author: russelltg

src/DataModelRegistry.hpp

@@ -34,13 +34,11 @@ class NODE_EDITOR_PUBLIC DataModelRegistry
 
   template<typename ModelType>
   void
-  registerModel()
+  registerModel(std::unique_ptr<ModelType> uniqueModel = std::make_unique<ModelType>())
   {
     static_assert(std::is_base_of<NodeDataModel, ModelType>::value,
                   "Must pass a subclass of NodeDataModel to registerModel");
 
-    auto uniqueModel = std::make_unique<ModelType>();
-
     QString const name = uniqueModel->name();
 
     if (_registeredModels.count(name) == 0)