fix feature export

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/CityDoctorController.java

@@ -1196,8 +1196,10 @@ public class CityDoctorController {
         if (model == null) {
             return;
         }
-        CityDoctorModel newModel = new CityDoctorModel(model.getParserConfig(), model.getFile(), new UnconnectedCache());
-        newModel.setCityModel(new CityModel());
+        UnconnectedCache cache = new UnconnectedCache();
+		CityDoctorModel newModel = new CityDoctorModel(model.getParserConfig(), model.getFile(), cache);
+        cache.put(co);
+		newModel.setCityModel(new CityModel());
         newModel.addCityObject(co);
         newModel.setParsedCityGMLVersion(model.getCityGMLVersion());
         newModel.getCityModel().setBoundedBy(model.getCityModel().getBoundedBy());