--- InsightToolkit-4.9.1/Modules/Segmentation/LevelSetsv4/include/itkLevelSetQuadEdgeMesh.hxx~	2016-04-12 12:51:54.000000000 -0400
+++ InsightToolkit-4.9.1/Modules/Segmentation/LevelSetsv4/include/itkLevelSetQuadEdgeMesh.hxx	2017-07-12 23:38:31.295766730 -0400
@@ -47,7 +47,7 @@
 LevelSetQuadEdgeMesh< TMesh >::EvaluateGradient( const InputType& itkNotUsed(iP) ) const
 {
   itkWarningMacro( <<"to be implemented" );
-  return this->GradientType();
+  return NULL; // this->GradientType();
 }
 
 template< typename TMesh >
@@ -55,7 +55,7 @@
 LevelSetQuadEdgeMesh< TMesh >::EvaluateHessian( const InputType& itkNotUsed(iP) ) const
 {
   itkWarningMacro( <<"to be implemented" );
-  return this->HessianType();
+  return NULL; // this->HessianType();
 }
 
 template< typename TMesh >