add a unit test Signed-off-by: Daniel Nephin <dnephin@docker.com> Upstream-commit: 07b59ef210490df19f65da950d7d41176d104a31 Component: engine
add a unit test Signed-off-by: Daniel Nephin <dnephin@docker.com> Upstream-commit: 07b59ef210490df19f65da950d7d41176d104a31 Component: engine