>>> import Designable.Proxies
>>> layout = Designable.Proxies.Layout3D()
>>> layout
[]
>>> import Point3D
>>> x = Point3D(0., 0., 0.)
Traceback (most recent call last):
  File "<console>", line 1, in <module>
TypeError: 'module' object is not callable
>>> x = Point3D.Point3D(0., 0., 0.)
>>> y = Point3D.Point3D(1., 0., 0.)
>>> layout.add_node(x, 0)
>>> layout.add_node(y, 0)
>>> layout.pop_node()
type super: <type 'super'>
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "./Designable/Proxies.py", line 290, in pop_node
TypeError: 'super' object is not subscriptable