Adapted VtkReader

src/example4.cc

@@ -58,7 +58,7 @@ int main(int argc, char** argv)
   GridFactory<GridType> factory;
   GridCreator creator(factory);
 
-  VtkReader reader(creator);
+  Vtk::VtkReader reader(creator);
   reader.read("sphere_order3.vtu");
   std::unique_ptr grid = reader.createGrid();