diff --git a/dumux/io/vtkoutputmodule.hh b/dumux/io/vtkoutputmodule.hh
index e7e3f7187f31755d6e52940ab66bc502c8706645..b053d330ef769455730a42d227cd817717ad31a9 100644
--- a/dumux/io/vtkoutputmodule.hh
+++ b/dumux/io/vtkoutputmodule.hh
@@ -45,163 +45,162 @@
 #include <dumux/common/parameters.hh>
 #include <dumux/discretization/methods.hh>
 
-namespace Dumux
-{
+namespace Dumux {
+namespace Vtk {
 
-namespace Vtk
+//! struct that can hold any field that fulfills the VTKFunction interface
+template<class GridView>
+class Field
 {
-    //! struct that can hold any field that fulfills the VTKFunction interface
-    template<class GridView>
-    class Field
-    {
-        enum { dim = GridView::dimension };
-        using ctype = typename GridView::ctype;
-        using Element = typename GridView::template Codim<0>::Entity;
+    enum { dim = GridView::dimension };
+    using ctype = typename GridView::ctype;
+    using Element = typename GridView::template Codim<0>::Entity;
 
-        // a VTK function that supports both scalar and vector values for each element
+    // a VTK function that supports both scalar and vector values for each element
 #if DUNE_VERSION_NEWER(DUNE_COMMON,2,6)
-        template <typename F>
-        struct VectorP0VTKFunction : Dune::VTKFunction<GridView>
-        {
-            using Mapper = Dune::MultipleCodimMultipleGeomTypeMapper<GridView>;
+    template <typename F>
+    struct VectorP0VTKFunction : Dune::VTKFunction<GridView>
+    {
+        using Mapper = Dune::MultipleCodimMultipleGeomTypeMapper<GridView>;
 #else
-        template<typename F, typename Mapper>
-        struct VectorP0VTKFunction : Dune::VTKFunction<GridView>
-        {
+    template<typename F, typename Mapper>
+    struct VectorP0VTKFunction : Dune::VTKFunction<GridView>
+    {
 #endif
-        public:
-            //! return number of components
-            virtual int ncomps () const
-            { return nComps_; }
-
-            //! evaluate
-            virtual double evaluate (int mycomp, const Element& e,
-                                     const Dune::FieldVector<ctype,dim>&) const
-            { return accessChooser_(mycomp, mapper_.index(e), Dune::is_indexable<decltype(field_[0])>()); }
-
-            //! get name
-            virtual std::string name () const
-            { return name_; }
-
-            VectorP0VTKFunction(const GridView &gridView, const Mapper& mapper, const F& field, const std::string& name, int nComps)
-            : field_(field), name_(name), nComps_(nComps), mapper_(mapper)
-            {
-                if (field.size()!=(unsigned int)(gridView.size(0)))
-                    DUNE_THROW(Dune::IOError, "NestedP0VTKFunction: size mismatch");
-            }
-        private:
-            double accessChooser_(int mycomp, int i, std::true_type) const
-            { return field_[i][mycomp]; }
+    public:
+        //! return number of components
+        virtual int ncomps () const
+        { return nComps_; }
 
-            double accessChooser_(int mycomp, int i, std::false_type) const
-            { return field_[i]; }
+        //! evaluate
+        virtual double evaluate (int mycomp, const Element& e,
+                                 const Dune::FieldVector<ctype,dim>&) const
+        { return accessChooser_(mycomp, mapper_.index(e), Dune::is_indexable<decltype(field_[0])>()); }
 
-            const F& field_;
-            const std::string name_;
-            int nComps_;
-            const Mapper& mapper_;
-        };
+        //! get name
+        virtual std::string name () const
+        { return name_; }
 
-        // a VTK function that supports both scalar and vector values for each vertex
-#if DUNE_VERSION_NEWER(DUNE_COMMON,2,6)
-        template <typename F>
-        struct VectorP1VTKFunction : Dune::VTKFunction<GridView>
+        VectorP0VTKFunction(const GridView &gridView, const Mapper& mapper, const F& field, const std::string& name, int nComps)
+        : field_(field), name_(name), nComps_(nComps), mapper_(mapper)
         {
-            using Mapper = Dune::MultipleCodimMultipleGeomTypeMapper<GridView>;
+            if (field.size()!=(unsigned int)(gridView.size(0)))
+                DUNE_THROW(Dune::IOError, "NestedP0VTKFunction: size mismatch");
+        }
+    private:
+        double accessChooser_(int mycomp, int i, std::true_type) const
+        { return field_[i][mycomp]; }
+
+        double accessChooser_(int mycomp, int i, std::false_type) const
+        { return field_[i]; }
+
+        const F& field_;
+        const std::string name_;
+        int nComps_;
+        const Mapper& mapper_;
+    };
+
+    // a VTK function that supports both scalar and vector values for each vertex
+#if DUNE_VERSION_NEWER(DUNE_COMMON,2,6)
+    template <typename F>
+    struct VectorP1VTKFunction : Dune::VTKFunction<GridView>
+    {
+        using Mapper = Dune::MultipleCodimMultipleGeomTypeMapper<GridView>;
 #else
-        template<typename F, typename Mapper>
-        struct VectorP1VTKFunction : Dune::VTKFunction<GridView>
-        {
+    template<typename F, typename Mapper>
+    struct VectorP1VTKFunction : Dune::VTKFunction<GridView>
+    {
 #endif
-        public:
-            //! return number of components
-            virtual int ncomps () const
-            { return nComps_; }
-
-            //! evaluate
-            virtual double evaluate (int mycomp, const Element& e,
-                                     const Dune::FieldVector<ctype,dim>& xi) const
-            {
-                const unsigned int dim = Element::mydimension;
-                const unsigned int nVertices = e.subEntities(dim);
+    public:
+        //! return number of components
+        virtual int ncomps () const
+        { return nComps_; }
+
+        //! evaluate
+        virtual double evaluate (int mycomp, const Element& e,
+                                 const Dune::FieldVector<ctype,dim>& xi) const
+        {
+            const unsigned int dim = Element::mydimension;
+            const unsigned int nVertices = e.subEntities(dim);
 
-                std::vector<Dune::FieldVector<ctype, 1>> cornerValues(nVertices);
-                for (unsigned i = 0; i < nVertices; ++i)
-                    cornerValues[i] = accessChooser_(mycomp, mapper_.subIndex(e, i, dim), Dune::is_indexable<decltype(field_[0])>());
+            std::vector<Dune::FieldVector<ctype, 1>> cornerValues(nVertices);
+            for (unsigned i = 0; i < nVertices; ++i)
+                cornerValues[i] = accessChooser_(mycomp, mapper_.subIndex(e, i, dim), Dune::is_indexable<decltype(field_[0])>());
 
-                // (Ab)use the MultiLinearGeometry class to do multi-linear interpolation between scalars
-                const Dune::MultiLinearGeometry<ctype, dim, 1> interpolation(e.type(), std::move(cornerValues));
-                return interpolation.global(xi);
-            }
+            // (Ab)use the MultiLinearGeometry class to do multi-linear interpolation between scalars
+            const Dune::MultiLinearGeometry<ctype, dim, 1> interpolation(e.type(), std::move(cornerValues));
+            return interpolation.global(xi);
+        }
 
-            //! get name
-            virtual std::string name () const
-            { return name_; }
+        //! get name
+        virtual std::string name () const
+        { return name_; }
 
-            VectorP1VTKFunction(const GridView &gridView, const Mapper& mapper, const F& field, const std::string& name, int nComps)
-            : field_(field), name_(name), nComps_(nComps), mapper_(mapper)
-            {
-                if (field.size()!=(unsigned int)(gridView.size(GridView::dimension)))
-                    DUNE_THROW(Dune::IOError, "NestedP1VTKFunction: size mismatch");
-            }
-        private:
-            double accessChooser_(int mycomp, int i, std::true_type) const
-            { return field_[i][mycomp]; }
+        VectorP1VTKFunction(const GridView &gridView, const Mapper& mapper, const F& field, const std::string& name, int nComps)
+        : field_(field), name_(name), nComps_(nComps), mapper_(mapper)
+        {
+            if (field.size()!=(unsigned int)(gridView.size(GridView::dimension)))
+                DUNE_THROW(Dune::IOError, "NestedP1VTKFunction: size mismatch");
+        }
+    private:
+        double accessChooser_(int mycomp, int i, std::true_type) const
+        { return field_[i][mycomp]; }
 
-            double accessChooser_(int mycomp, int i, std::false_type) const
-            { return field_[i]; }
+        double accessChooser_(int mycomp, int i, std::false_type) const
+        { return field_[i]; }
 
-            const F& field_;
-            const std::string name_;
-            int nComps_;
-            const Mapper& mapper_;
-        };
+        const F& field_;
+        const std::string name_;
+        int nComps_;
+        const Mapper& mapper_;
+    };
 
-    public:
-        // template constructor selects the right VTKFunction implementation
-        template <typename F, class Mapper>
-        Field(const GridView& gridView, const Mapper& mapper, F const& f,
-              const std::string& name, int numComp = 1, int codim = 0)
-        : codim_(codim)
-        {
-            if (codim == GridView::dimension)
+public:
+    // template constructor selects the right VTKFunction implementation
+    template <typename F, class Mapper>
+    Field(const GridView& gridView, const Mapper& mapper, F const& f,
+          const std::string& name, int numComp = 1, int codim = 0)
+    : codim_(codim)
+    {
+        if (codim == GridView::dimension)
 #if DUNE_VERSION_NEWER(DUNE_COMMON,2,6)
-                field_ = std::make_shared<VectorP1VTKFunction<F>>(gridView, mapper, f, name, numComp);
+            field_ = std::make_shared<VectorP1VTKFunction<F>>(gridView, mapper, f, name, numComp);
 #else
-                field_ = std::make_shared<VectorP1VTKFunction<F, Mapper>>(gridView, mapper, f, name, numComp);
+            field_ = std::make_shared<VectorP1VTKFunction<F, Mapper>>(gridView, mapper, f, name, numComp);
 #endif
-            else if (codim == 0)
+        else if (codim == 0)
 #if DUNE_VERSION_NEWER(DUNE_COMMON,2,6)
-                field_ = std::make_shared<VectorP0VTKFunction<F>>(gridView, mapper, f, name, numComp);
+            field_ = std::make_shared<VectorP0VTKFunction<F>>(gridView, mapper, f, name, numComp);
 #else
-                field_ = std::make_shared<VectorP0VTKFunction<F, Mapper>>(gridView, mapper, f, name, numComp);
+            field_ = std::make_shared<VectorP0VTKFunction<F, Mapper>>(gridView, mapper, f, name, numComp);
 #endif
-            else
-                DUNE_THROW(Dune::NotImplemented, "Only element or vertex quantities allowed.");
-        }
+        else
+            DUNE_THROW(Dune::NotImplemented, "Only element or vertex quantities allowed.");
+    }
 
-        virtual std::string name () const
-        { return field_->name(); }
+    virtual std::string name () const
+    { return field_->name(); }
 
-        virtual int ncomps() const
-        { return field_->ncomps(); }
+    virtual int ncomps() const
+    { return field_->ncomps(); }
 
-        virtual double evaluate(int mycomp,
-                                const Element &element,
-                                const Dune::FieldVector< ctype, dim > &xi) const
-        { return field_->evaluate(mycomp, element, xi); }
+    virtual double evaluate(int mycomp,
+                            const Element &element,
+                            const Dune::FieldVector< ctype, dim > &xi) const
+    { return field_->evaluate(mycomp, element, xi); }
 
-        int codim() const
-        { return codim_; }
+    int codim() const
+    { return codim_; }
 
-        const std::shared_ptr<Dune::VTKFunction<GridView>>& get() const
-        { return field_; }
+    const std::shared_ptr<Dune::VTKFunction<GridView>>& get() const
+    { return field_; }
+
+private:
+    int codim_;
+    // can point to anything fulfilling the VTKFunction interface
+    std::shared_ptr<Dune::VTKFunction<GridView>> field_;
+};
 
-    private:
-        int codim_;
-        // can point to anything fulfilling the VTKFunction interface
-        std::shared_ptr<Dune::VTKFunction<GridView>> field_;
-    };
 } // end namespace Vtk
 
 /*!