'Returns the group ID, or None if none is available.'

def get_group_id(self):

    partitions_service = self.runtime.service(self, 'partitions')
    user_service = self.runtime.service(self, 'user')
    user = user_service._django_user
    return partitions_service.get_user_group_id_for_partition(user, self.user_partition_id)
