def explode_contact_groups_into_contacts(item, contactgroups):
        if not hasattr(item, 'contact_groups'):
            return
        cgnames = ''
        if item.contact_groups:
            if isinstance(item.contact_groups, list):
                cgnames = item.contact_groups
            else:
                cgnames = item.contact_groups.split(',')
        cgnames = strip_and_uniq(cgnames)
        for cgname in cgnames:
            contactgroup = contactgroups.find_by_name(cgname)
            if not contactgroup:
                item.add_error("The contact group '%s' defined on the %s '%s' do not exist"
                               % (cgname, item.__class__.my_type, item.get_name()))
                continue
            cnames = contactgroups.get_members_of_group(cgname)
            if cnames:
                if hasattr(item, 'contacts'):
                    item.contacts = item.contacts + cnames
                else:
                    item.contacts = cnames