def METHOD_NAME(self, config_opts):
    """ Allow a different mock group to be specified.
        This tries to solve chicken-egg problem. Because the uidManager
        has to be initialized before reading config, but config_opts['chrootgid']
        is known only after reading config
    """
    if config_opts['chrootgid'] != self.mockgid:
        self.restorePrivs()
        os.setgroups((self.mockgid, config_opts['chrootgid']))
        self.dropPrivsTemp()