docs: def remove_router_interface(self, context, router_id, interface_info):
          """Remove a subnet of a network from an existing router."""
  
          router_to_del = (
              super(AristaL3ServicePlugin, self).remove_router_interface(
                  context,
                  router_id,
                  interface_info)
              )
  
          # Get network information of the subnet that is being removed
          core = directory.get_plugin()
          subnet = core.get_subnet(context, router_to_del['subnet_id'])
          network_id = subnet['network_id']
  
          # For SVI removal from Arista HW, segmentation ID is needed
          ml2_db = NetworkContext(self, context, {'id': network_id})
          seg_id = ml2_db.network_segments[0]['segmentation_id']
  
          router = self.get_router(context, router_id)
          router_info = copy.deepcopy(router_to_del)
          router_info['seg_id'] = seg_id
          router_info['name'] = router['name']
  
          try:
              self.driver.remove_router_interface(context, router_info)
              return router_to_del
          except Exception as exc:
              LOG.error(_LE("Error removing interface %(interface)s from "
                            "router %(router_id)s on Arista HW"
                            "Exception =(exc)s"),
                        {'interface': interface_info, 'router_id': router_id,
                         'exc': exc})