virtual vtkIdType GetNumberOfClippingPlanes();
virtual vtkPlane* GetClippingPlane(vtkIdType theID);
virtual vtkIdType AddClippingPlane(vtkPlane* thePlane);
virtual vtkIdType GetNumberOfClippingPlanes();
virtual vtkPlane* GetClippingPlane(vtkIdType theID);
virtual vtkIdType AddClippingPlane(vtkPlane* thePlane);