PyAlgorithmExample.Z Node1 PyAlgorithmExample.Z + __init__() + dr() Node2 PyAlgorithmExample.PyComposite Particle - __l + __init__() + add() + __len__() + __getitem__() + __iter__() + __contains__() + append() + extend() + count() + index() Node2->Node1 Node3 g::CompositeParticle Node3->Node2