How to test (it should not print `{}`, and just returns JSON with the actual data):
$ docker images --format '{{json .}}'
$ docker container stats --format '{{json .}}'
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Upstream-commit: 26013fcdd64221c858022392a1430a6c43eaaa26
Component: engine