[Zope] What kind of attributes can be put inside a simple item

[Marco Bizzarri]

Hi all.

I'm little surprised by the possibility to insert non-persistent 
instances inside persistent object. I mean:

class Alfa:
	def __init__(self):
		self.x = 1
		self.y = 2


class Beta(SimpleItem):
	def __init__(self):
		self.id = 'anId'
		self.anAlfa = Alfa()


I always understood that I could not put Alfa instances inside a Beta 
class, because the ZODB machinery did not understood how to pickle them. 
But I did some experiments recently, and it looks like the above example 
should work.

Could anyone provide some insight on this topic?

Thanks

Regards
Marco