code: def get_out_net_id(cls, tenant_id):
          
          if 'out' not in cls.ip_db_obj:
              LOG.error("Fabric not prepared for tenant %s", tenant_id)
              return None
          db_obj = cls.ip_db_obj.get('out')
          out_subnet_dict = cls.get_out_ip_addr(tenant_id)
          sub = db_obj.get_subnet(out_subnet_dict.get('subnet'))
          return sub.network_id
docs: Retrieve the network ID of OUT network.