ommit 1ae9059360dad8c0614b1bbce5f16dd0f8c0898c
Author: duguhaotian <knowledgehao@163.com>
Date:   Sun May 24 16:54:55 2020 +0800

    support keep all keys and values even unkonwn
Signed-off-by: Nhaozi007 <liuhao27@huawei.com>