code: def delete_intf_router(self, tenant_id, tenant_name, router_id):
          
          in_sub = self.get_in_subnet_id(tenant_id)
          out_sub = self.get_out_subnet_id(tenant_id)
          subnet_lst = set()
          subnet_lst.add(in_sub)
          subnet_lst.add(out_sub)
          router_id = self.get_router_id(tenant_id, tenant_name)
          if router_id:
              ret = self.os_helper.delete_intf_router(tenant_name, tenant_id,
                                                      router_id, subnet_lst)
              if not ret:
                  LOG.error("Failed to delete router intf id %(rtr)s, "
                            "tenant %(tenant)s",
                            {'rtr': router_id, 'tenant': tenant_id})
              return ret
          LOG.error("Invalid router ID, can't delete interface from "
                    "router")
docs: Routine to delete the router.