class C: bb = Collection(B)
class A: bs = Collection(B)
class B: zaa = Collection(A) c = Uplink()
class Big: smalls = Collection(Small)
class Up: id = 0 downs = Collection(Down)
class B: a = Collection(A)
class B: values = Collection(A)
class B: a = Unique(A) ma = Maybe(Unique(A)) aa = Collection(A)
class D: bs = Collection(B)
class B(object): a_s = Collection(A)
class Player(object): name = '' squads = Collection(Squad)
class Squad(object): name = '' units = Collection(Unit) leader = Unique(Hero) player = Uplink()