Comitting incase I break something

src/dawntools/scenetool/SceneParser.cpp

@@ -12,7 +12,9 @@ std::vector<std::string> SceneParser::getRequiredAttributes() {
 }
 
 std::map<std::string, std::string> SceneParser::getOptionalAttributes() {
-  return {};
+  return {
+    { "extend", "" }
+  };
 }
 
 int32_t SceneParser::onParse(
@@ -25,6 +27,7 @@ int32_t SceneParser::onParse(
 
   //Create the scene item
   out->name = values["name"];
+  out->extend = values["extend"];
 
   //Parse the children
   auto itChildren = node->children.begin();

src/dawntools/scenetool/SceneParser.hpp

@@ -9,6 +9,7 @@
 namespace Dawn {
   struct Scene {
     std::string name;
+    std::string extend;
     std::vector<struct SceneItem> items;
     struct SceneItemComponentRegistry *registry;
   };