diff --git a/GUI/Models/GUIObjectBuilder.cpp b/GUI/Models/GUIObjectBuilder.cpp
index 1a4dbbaa84569d4b5ec7daed1f589e122e9f1c16..d309663a18b12967a04d8c66ebef7c60cb67af01 100644
--- a/GUI/Models/GUIObjectBuilder.cpp
+++ b/GUI/Models/GUIObjectBuilder.cpp
@@ -24,19 +24,55 @@
 #include "GUI/Models/TransformFromDomain.h"
 
 namespace {
+
 GISASInstrumentItem* createGISASInstrumentItem(InstrumentModel* model,
                                                const GISASSimulation& simulation,
-                                               const QString& name);
+                                               const QString& name)
+{
+    auto result = model->insertItem<GISASInstrumentItem>();
+    result->setItemName(name);
+    GUI::Transform::FromDomain::setGISASBeamItem(result->beamItem(), simulation);
+    GUI::Transform::FromDomain::setDetector(result, simulation);
+    GUI::Transform::FromDomain::setBackground(result, simulation);
+
+    return result;
+}
 
 OffSpecularInstrumentItem* createOffSpecularInstrumentItem(InstrumentModel* model,
                                                            const OffSpecularSimulation& simulation,
-                                                           const QString& name);
+                                                           const QString& name)
+{
+    auto result = model->insertItem<OffSpecularInstrumentItem>();
+    result->setItemName(name);
+    GUI::Transform::FromDomain::setOffSpecularBeamItem(result->beamItem(), simulation);
+    GUI::Transform::FromDomain::setDetector(result, simulation);
+    GUI::Transform::FromDomain::setBackground(result, simulation);
+
+    BasicAxisItem* axisItem = result->alphaAxis();
+    ASSERT(axisItem);
+    GUI::Transform::FromDomain::setAxisItem(axisItem, *simulation.beamAxis(), 1. / Units::deg);
+
+    return result;
+}
 
 SpecularInstrumentItem* createSpecularInstrumentItem(InstrumentModel* model,
                                                      const SpecularSimulation& simulation,
-                                                     const QString& name);
+                                                     const QString& name)
+{
+    auto result = model->insertItem<SpecularInstrumentItem>();
+    result->setItemName(name);
+    GUI::Transform::FromDomain::setSpecularBeamItem(result->beamItem(), simulation);
+    GUI::Transform::FromDomain::setBackground(result, simulation);
+
+    return result;
+}
+
 } // namespace
 
+//  ************************************************************************************************
+//  class implementation
+//  ************************************************************************************************
+
 SessionItem* GUI::Model::ObjectBuilder::populateSampleModel(SampleModel* sampleModel,
                                                             MaterialModel* materialModel,
                                                             const MultiLayer& sample,
@@ -83,47 +119,3 @@ SessionItem* GUI::Model::ObjectBuilder::populateDocumentModel(DocumentModel* p_d
 
     return item;
 }
-
-namespace {
-GISASInstrumentItem* createGISASInstrumentItem(InstrumentModel* model,
-                                               const GISASSimulation& simulation,
-                                               const QString& name)
-{
-    auto result = model->insertItem<GISASInstrumentItem>();
-    result->setItemName(name);
-    GUI::Transform::FromDomain::setGISASBeamItem(result->beamItem(), simulation);
-    GUI::Transform::FromDomain::setDetector(result, simulation);
-    GUI::Transform::FromDomain::setBackground(result, simulation);
-
-    return result;
-}
-
-OffSpecularInstrumentItem* createOffSpecularInstrumentItem(InstrumentModel* model,
-                                                           const OffSpecularSimulation& simulation,
-                                                           const QString& name)
-{
-    auto result = model->insertItem<OffSpecularInstrumentItem>();
-    result->setItemName(name);
-    GUI::Transform::FromDomain::setOffSpecularBeamItem(result->beamItem(), simulation);
-    GUI::Transform::FromDomain::setDetector(result, simulation);
-    GUI::Transform::FromDomain::setBackground(result, simulation);
-
-    BasicAxisItem* axisItem = result->alphaAxis();
-    ASSERT(axisItem);
-    GUI::Transform::FromDomain::setAxisItem(axisItem, *simulation.beamAxis(), 1. / Units::deg);
-
-    return result;
-}
-
-SpecularInstrumentItem* createSpecularInstrumentItem(InstrumentModel* model,
-                                                     const SpecularSimulation& simulation,
-                                                     const QString& name)
-{
-    auto result = model->insertItem<SpecularInstrumentItem>();
-    result->setItemName(name);
-    GUI::Transform::FromDomain::setSpecularBeamItem(result->beamItem(), simulation);
-    GUI::Transform::FromDomain::setBackground(result, simulation);
-
-    return result;
-}
-} // namespace