[Zope] Getting inherited classes

[Michele Ruberl]

Hi all,
a quick question: how could I (in a python script) get a list of all 
inherited classes from an object's meta_type? My aim's is to get the 
first object implementing ObjectManager while going up in the PARENTS 
hierarchy, whith something like that:

parents = request.PARENTS
for i in range(len(parents)):
    if parents[i].meta_type ********:    ### if it implements ObjectManagers
        return parents[i]


Ciao

Mik