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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_vrf_name(self, ri):
 """ overloaded method for generating a vrf_name that supports region_id """

        router_id = ri.router_name()[:self.DEV_NAME_LEN]
        is_multi_region_enabled = cfg.CONF.multi_region.enable_multi_region

        if is_multi_region_enabled:
            region_id = cfg.CONF.multi_region.region_id
            vrf_name = "%s-%s" % (router_id, region_id)
        else:
            vrf_name = router_id
        return vrf_name