dia python plugin, how to store temporary information during export

[Sebastian Setzer <SebastianSetzer alice-dsl net>]

Hi,
is there some way to store information in the dia objects during export
with a python plugin?

For example, I want to give each state of a UML state diagram a unique
number.

I can store that information in a dictionary with the object as key. But
that's inconvenient because I have to pass this dictionary around. So I
wonder if there's a better way.

Just assigning to a new member of the objects or adding "properties"
doesn't seem to work.

Sebastian