diff --git a/dune/solvers/iterationsteps/multigridstep.cc b/dune/solvers/iterationsteps/multigridstep.cc
index 717d5761dbc3f19df2257918beece311259e4a47..1bd539d76b0fe05288adc11318932bdd8b70b850 100644
--- a/dune/solvers/iterationsteps/multigridstep.cc
+++ b/dune/solvers/iterationsteps/multigridstep.cc
@@ -49,7 +49,7 @@ setMGType(int mu, int nu1, int nu2)
  *  \li transfer operators
  *  \li fine level matrix, solution vector and right hand side
  *  \li smoothers
- *  have to be set prior to the call to preprocess(). 
+ *  have to be set prior to the call to preprocess().
  *  If any is changed subsequently, preprocess() has to be called again before iterate().
  *  There is one exception. The right hand side may be changed by setRhs() without a subsequent call to preprocess().
  *  This is in order to be able to compute solutions to multiple rhs w/o having to reassemble the same matrix hierarchy time and again.
@@ -121,7 +121,7 @@ void MultigridStep<MatrixType, VectorType, BitVectorType>::preprocess()
         this->xHierarchy_[i] = std::shared_ptr<VectorType>(new VectorType);
 
         // Compute which entries are present in the (sparse) coarse grid stiffness
-        // matrices. 
+        // matrices.
         this->mgTransfer_[i]->galerkinRestrictSetOccupation(*this->matrixHierarchy_[i+1], *std::const_pointer_cast<MatrixType>(this->matrixHierarchy_[i]));
 
         // setup matrix
@@ -161,21 +161,21 @@ void MultigridStep<MatrixType, VectorType, BitVectorType>::preprocess()
     if (typeid(*this->basesolver_) == typeid(DuneSolversLoopSolver)) {
 
         DuneSolversLoopSolver* loopBaseSolver = dynamic_cast<DuneSolversLoopSolver*> (this->basesolver_);
-     
+
         typedef LinearIterationStep<MatrixType, VectorType> SmootherType;
         assert(dynamic_cast<SmootherType*>(loopBaseSolver->iterationStep_));
 
         dynamic_cast<SmootherType*>(loopBaseSolver->iterationStep_)->setProblem(*(this->matrixHierarchy_[0]), *this->xHierarchy_[0], this->rhsHierarchy_[0]);
         dynamic_cast<SmootherType*>(loopBaseSolver->iterationStep_)->ignoreNodes_ = ignoreNodesHierarchy_[0];
-        
+
     }
 #if HAVE_IPOPT
     else if (typeid(*this->basesolver_) == typeid(QuadraticIPOptSolver<MatrixType,VectorType>)) {
 
         QuadraticIPOptSolver<MatrixType,VectorType>* ipoptBaseSolver = dynamic_cast<QuadraticIPOptSolver<MatrixType,VectorType>*> (this->basesolver_);
-     
+
         ipoptBaseSolver->setProblem(*(this->matrixHierarchy_[0]), *this->xHierarchy_[0], this->rhsHierarchy_[0]);
-    } 
+    }
 #endif
 else {
         DUNE_THROW(SolverError, "You can't use " << typeid(*this->basesolver_).name()