[vtkusers] Number of points in a KdTree?

[David Doria]

vtkSmartPointer<vtkPoints> Points = vtkSmartPointer<vtkPoints>::New();
// ... add points
  vtkSmartPointer<vtkKdTree> Tree = vtkSmartPointer<vtkKdTree>::New();
  Tree->BuildLocatorFromPoints(Points);

Now if I only have the tree object, how would I get the number of
points it contains?

Thanks,

David