code: def _fw_rule_delete(self, drvr_name, data):
          
          rule_id = data.get('firewall_rule_id')
          tenant_id = self.tenant_db.get_rule_tenant(rule_id)
  
          if tenant_id not in self.fwid_attr:
              LOG.error("Invalid tenant id for FW delete %s", tenant_id)
              return
          tenant_obj = self.fwid_attr[tenant_id]
          # Guess actual FW/policy need not be deleted if this is the active
          # rule, Openstack does not allow it to be deleted
          tenant_obj.delete_rule(rule_id)
          self.tenant_db.del_rule_tenant(rule_id)
docs: Function that updates its local cache after a rule is deleted.