diff --git a/Plugins/org.mitk.gui.qt.multilabelsegmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp b/Plugins/org.mitk.gui.qt.multilabelsegmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp
index 87c10cacf2..874d15aefb 100644
--- a/Plugins/org.mitk.gui.qt.multilabelsegmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp
+++ b/Plugins/org.mitk.gui.qt.multilabelsegmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp
@@ -1,140 +1,143 @@
 /*============================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center (DKFZ)
 All rights reserved.
 
 Use of this source code is governed by a 3-clause BSD license that can be
 found in the LICENSE file.
 
 ============================================================================*/
 
 #include "QmitkBooleanOperationsWidget.h"
 #include "../../Common/QmitkDataSelectionWidget.h"
 #include <mitkException.h>
 #include <mitkSliceNavigationController.h>
 #include <cassert>
 
 static const char* const HelpText = "Select two different masks above";
 
-std::string GetPrefix(mitk::BooleanOperation::Type type)
+namespace
 {
-  switch (type)
+  std::string GetPrefix(mitk::BooleanOperation::Type type)
   {
-    case mitk::BooleanOperation::Difference:
-      return "DifferenceFrom_";
+    switch (type)
+    {
+      case mitk::BooleanOperation::Difference:
+        return "DifferenceFrom_";
 
-    case mitk::BooleanOperation::Intersection:
-      return "IntersectionWith_";
+      case mitk::BooleanOperation::Intersection:
+        return "IntersectionWith_";
 
-    case mitk::BooleanOperation::Union:
-      return "UnionWith_";
+      case mitk::BooleanOperation::Union:
+        return "UnionWith_";
 
-    default:
-      assert(false && "Unknown boolean operation type");
-      return "UNKNOWN_BOOLEAN_OPERATION_WITH_";
+      default:
+        assert(false && "Unknown boolean operation type");
+        return "UNKNOWN_BOOLEAN_OPERATION_WITH_";
+    }
   }
-}
 
-void AddToDataStorage(mitk::DataStorage::Pointer dataStorage, mitk::Image::Pointer segmentation, const std::string& name, mitk::DataNode::Pointer parent = nullptr)
-{
-  mitk::DataNode::Pointer dataNode = mitk::DataNode::New();
+  void AddToDataStorage(mitk::DataStorage::Pointer dataStorage, mitk::Image::Pointer segmentation, const std::string& name, mitk::DataNode::Pointer parent = nullptr)
+  {
+    mitk::DataNode::Pointer dataNode = mitk::DataNode::New();
 
-  dataNode->SetBoolProperty("binary", true);
-  dataNode->SetName(name);
-  dataNode->SetData(segmentation);
+    dataNode->SetBoolProperty("binary", true);
+    dataNode->SetName(name);
+    dataNode->SetData(segmentation);
 
-  dataStorage->Add(dataNode, parent);
+    dataStorage->Add(dataNode, parent);
+  }
 }
 
 QmitkBooleanOperationsWidget::QmitkBooleanOperationsWidget(mitk::SliceNavigationController* timeNavigationController, QWidget* parent)
   : QmitkSegmentationUtilityWidget(timeNavigationController, parent)
 {
   m_Controls.setupUi(this);
 
   m_Controls.dataSelectionWidget->AddDataSelection(QmitkDataSelectionWidget::MaskPredicate);
   m_Controls.dataSelectionWidget->AddDataSelection(QmitkDataSelectionWidget::MaskPredicate);
 
   m_Controls.dataSelectionWidget->SetHelpText(HelpText);
 
   connect(m_Controls.dataSelectionWidget, SIGNAL(SelectionChanged(unsigned int, const mitk::DataNode*)), this, SLOT(OnSelectionChanged(unsigned int, const mitk::DataNode*)));
   connect(m_Controls.differenceButton, SIGNAL(clicked()), this, SLOT(OnDifferenceButtonClicked()));
   connect(m_Controls.intersectionButton, SIGNAL(clicked()), this, SLOT(OnIntersectionButtonClicked()));
   connect(m_Controls.unionButton, SIGNAL(clicked()), this, SLOT(OnUnionButtonClicked()));
 }
 
 QmitkBooleanOperationsWidget::~QmitkBooleanOperationsWidget()
 {
 }
 
 void QmitkBooleanOperationsWidget::OnSelectionChanged(unsigned int, const mitk::DataNode*)
 {
   QmitkDataSelectionWidget* dataSelectionWidget = m_Controls.dataSelectionWidget;
 
   mitk::DataNode::Pointer node0 = dataSelectionWidget->GetSelection(0);
   mitk::DataNode::Pointer node1 = dataSelectionWidget->GetSelection(1);
 
   if (node0.IsNotNull() && node1.IsNotNull() && node0 != node1)
   {
     dataSelectionWidget->SetHelpText("");
     this->EnableButtons();
   }
   else
   {
     dataSelectionWidget->SetHelpText(HelpText);
     this->EnableButtons(false);
   }
 }
 
 void QmitkBooleanOperationsWidget::EnableButtons(bool enable)
 {
   m_Controls.differenceButton->setEnabled(enable);
   m_Controls.intersectionButton->setEnabled(enable);
   m_Controls.unionButton->setEnabled(enable);
 }
 
 void QmitkBooleanOperationsWidget::OnDifferenceButtonClicked()
 {
   this->DoBooleanOperation(mitk::BooleanOperation::Difference);
 }
 
 void QmitkBooleanOperationsWidget::OnIntersectionButtonClicked()
 {
   this->DoBooleanOperation(mitk::BooleanOperation::Intersection);
 }
 
 void QmitkBooleanOperationsWidget::OnUnionButtonClicked()
 {
   this->DoBooleanOperation(mitk::BooleanOperation::Union);
 }
 
 void QmitkBooleanOperationsWidget::DoBooleanOperation(mitk::BooleanOperation::Type type)
 {
   mitk::SliceNavigationController* timeNavigationController = this->GetTimeNavigationController();
   assert(timeNavigationController != nullptr);
 
   mitk::Image::Pointer segmentation0 = static_cast<mitk::Image*>(m_Controls.dataSelectionWidget->GetSelection(0)->GetData());
   mitk::Image::Pointer segmentation1 = static_cast<mitk::Image*>(m_Controls.dataSelectionWidget->GetSelection(1)->GetData());
   mitk::Image::Pointer result;
 
   try
   {
     mitk::BooleanOperation booleanOperation(type, segmentation0, segmentation1, timeNavigationController->GetSelectedTimePoint());
     result = booleanOperation.GetResult();
   }
   catch (const mitk::Exception &exception)
   {
     MITK_ERROR << "Boolean operation failed: " << exception.GetDescription();
   }
 
   assert(result.IsNotNull());
 
   QmitkDataSelectionWidget* dataSelectionWidget = m_Controls.dataSelectionWidget;
 
   AddToDataStorage(
     dataSelectionWidget->GetDataStorage(),
     result,
     GetPrefix(type) + dataSelectionWidget->GetSelection(1)->GetName(),
     dataSelectionWidget->GetSelection(0));
 }
diff --git a/Plugins/org.mitk.gui.qt.segmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp b/Plugins/org.mitk.gui.qt.segmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp
index abb337ba5b..10322cfe9d 100644
--- a/Plugins/org.mitk.gui.qt.segmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp
+++ b/Plugins/org.mitk.gui.qt.segmentation/src/internal/SegmentationUtilities/BooleanOperations/QmitkBooleanOperationsWidget.cpp
@@ -1,141 +1,144 @@
 /*============================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center (DKFZ)
 All rights reserved.
 
 Use of this source code is governed by a 3-clause BSD license that can be
 found in the LICENSE file.
 
 ============================================================================*/
 
 #include "QmitkBooleanOperationsWidget.h"
 #include "../../Common/QmitkDataSelectionWidget.h"
 #include <mitkException.h>
 #include <mitkSliceNavigationController.h>
 #include <cassert>
 #include <QMessageBox>
 
 static const char* const HelpText = "Select two different segmentations above";
 
-static std::string GetPrefix(mitk::BooleanOperation::Type type)
+namespace
 {
-  switch (type)
+  static std::string GetPrefix(mitk::BooleanOperation::Type type)
   {
-    case mitk::BooleanOperation::Difference:
-      return "DifferenceFrom_";
+    switch (type)
+    {
+      case mitk::BooleanOperation::Difference:
+        return "DifferenceFrom_";
 
-    case mitk::BooleanOperation::Intersection:
-      return "IntersectionWith_";
+      case mitk::BooleanOperation::Intersection:
+        return "IntersectionWith_";
 
-    case mitk::BooleanOperation::Union:
-      return "UnionWith_";
+      case mitk::BooleanOperation::Union:
+        return "UnionWith_";
 
-    default:
-      assert(false && "Unknown boolean operation type");
-      return "UNKNOWN_BOOLEAN_OPERATION_WITH_";
+      default:
+        assert(false && "Unknown boolean operation type");
+        return "UNKNOWN_BOOLEAN_OPERATION_WITH_";
+    }
   }
-}
 
-static void AddToDataStorage(mitk::DataStorage::Pointer dataStorage, mitk::Image::Pointer segmentation, const std::string& name, mitk::DataNode::Pointer parent = nullptr)
-{
-  auto dataNode = mitk::DataNode::New();
+  static void AddToDataStorage(mitk::DataStorage::Pointer dataStorage, mitk::Image::Pointer segmentation, const std::string& name, mitk::DataNode::Pointer parent = nullptr)
+  {
+    auto dataNode = mitk::DataNode::New();
 
-  dataNode->SetName(name);
-  dataNode->SetData(segmentation);
+    dataNode->SetName(name);
+    dataNode->SetData(segmentation);
 
-  dataStorage->Add(dataNode, parent);
+    dataStorage->Add(dataNode, parent);
+  }
 }
 
 QmitkBooleanOperationsWidget::QmitkBooleanOperationsWidget(mitk::SliceNavigationController* timeNavigationController, QWidget* parent)
   : QmitkSegmentationUtilityWidget(timeNavigationController, parent)
 {
   m_Controls.setupUi(this);
 
   m_Controls.dataSelectionWidget->AddDataSelection("<img width=16 height=16 src=\":/SegmentationUtilities/BooleanLabelA_32x32.png\"/>", "Select 1st segmentation", "Select 1st segmentation", "", QmitkDataSelectionWidget::SegmentationPredicate);
   m_Controls.dataSelectionWidget->AddDataSelection("<img width=16 height=16 src=\":/SegmentationUtilities/BooleanLabelB_32x32.png\"/>", "Select 2nd segmentation", "Select 2nd segmentation", "", QmitkDataSelectionWidget::SegmentationPredicate);
 
   m_Controls.dataSelectionWidget->SetHelpText(HelpText);
 
   connect(m_Controls.dataSelectionWidget, SIGNAL(SelectionChanged(unsigned int, const mitk::DataNode*)), this, SLOT(OnSelectionChanged(unsigned int, const mitk::DataNode*)));
   connect(m_Controls.differenceButton, SIGNAL(clicked()), this, SLOT(OnDifferenceButtonClicked()));
   connect(m_Controls.intersectionButton, SIGNAL(clicked()), this, SLOT(OnIntersectionButtonClicked()));
   connect(m_Controls.unionButton, SIGNAL(clicked()), this, SLOT(OnUnionButtonClicked()));
 }
 
 QmitkBooleanOperationsWidget::~QmitkBooleanOperationsWidget()
 {
 }
 
 void QmitkBooleanOperationsWidget::OnSelectionChanged(unsigned int, const mitk::DataNode*)
 {
   auto dataSelectionWidget = m_Controls.dataSelectionWidget;
 
   auto nodeA = dataSelectionWidget->GetSelection(0);
   auto nodeB = dataSelectionWidget->GetSelection(1);
 
   if (nodeA.IsNotNull() && nodeB.IsNotNull() && nodeA != nodeB)
   {
     dataSelectionWidget->SetHelpText("");
     this->EnableButtons();
   }
   else
   {
     dataSelectionWidget->SetHelpText(HelpText);
     this->EnableButtons(false);
   }
 }
 
 void QmitkBooleanOperationsWidget::EnableButtons(bool enable)
 {
   m_Controls.differenceButton->setEnabled(enable);
   m_Controls.intersectionButton->setEnabled(enable);
   m_Controls.unionButton->setEnabled(enable);
 }
 
 void QmitkBooleanOperationsWidget::OnDifferenceButtonClicked()
 {
   this->DoBooleanOperation(mitk::BooleanOperation::Difference);
 }
 
 void QmitkBooleanOperationsWidget::OnIntersectionButtonClicked()
 {
   this->DoBooleanOperation(mitk::BooleanOperation::Intersection);
 }
 
 void QmitkBooleanOperationsWidget::OnUnionButtonClicked()
 {
   this->DoBooleanOperation(mitk::BooleanOperation::Union);
 }
 
 void QmitkBooleanOperationsWidget::DoBooleanOperation(mitk::BooleanOperation::Type type)
 {
   auto timeNavigationController = this->GetTimeNavigationController();
   assert(timeNavigationController != nullptr);
 
   mitk::Image::Pointer segmentationA = dynamic_cast<mitk::Image*>(m_Controls.dataSelectionWidget->GetSelection(0)->GetData());
   mitk::Image::Pointer segmentationB = dynamic_cast<mitk::Image*>(m_Controls.dataSelectionWidget->GetSelection(1)->GetData());
   mitk::Image::Pointer result;
 
   try
   {
     mitk::BooleanOperation booleanOperation(type, segmentationA, segmentationB, timeNavigationController->GetSelectedTimePoint());
     result = booleanOperation.GetResult();
 
     assert(result.IsNotNull());
 
     auto dataSelectionWidget = m_Controls.dataSelectionWidget;
 
     AddToDataStorage(
       dataSelectionWidget->GetDataStorage(),
       result,
       GetPrefix(type) + dataSelectionWidget->GetSelection(1)->GetName(),
       dataSelectionWidget->GetSelection(0));
   }
   catch (const mitk::Exception& exception)
   {
     MITK_ERROR << "Boolean operation failed: " << exception.GetDescription();
     QMessageBox::information(nullptr, "Boolean operation failed", exception.GetDescription());
   }
 }