46   static void FindTouchingSphereCenter(vtkPolyData* centerlines, 
const char* radiusArrayName, vtkIdType cellId, vtkIdType subId, 
double pcoord, vtkIdType& touchingSubId, 
double& touchingPCoord, 
bool forward=
true);
    48   static void FindNTouchingSphereCenter(vtkPolyData* centerlines, 
const char* radiusArrayName, vtkIdType cellId, vtkIdType subId, 
double pcoord, 
int numberOfTouchingSpheres, vtkIdType& touchingSubId, 
double& touchingPCoord, 
bool forward=
true);