'Callback to handle RBAC_POLICY, BEFORE_DELETE callback.
:raises: RbacPolicyInUse -- in case the policy is in use.'

@classmethod
def validate_rbac_policy_delete(cls, resource, event, trigger, context, object_type, policy, **kwargs):

    if (policy['action'] != models.ACCESS_SHARED):
        return
    target_tenant = policy['target_tenant']
    db_obj = obj_db_api.get_object(context.elevated(), cls.db_model, id=policy['object_id'])
    if (db_obj.tenant_id == target_tenant):
        return
    cls._validate_rbac_policy_delete(context=context, obj_id=policy['object_id'], target_tenant=target_tenant)
