Planemo test with containerized tools

I have build a docker container for a tool and want to use planemo for testing, like:

planemo test --docker --engine external_galaxy bwa-mem.xml

and in the tool XML, I have

        <container type="docker">bwa:latest</container>

Unfortunately, the docker container is not executed, instead the test want to execute “bwa” locally. Is that possible with planemo?

I think the best approach would be to upload the docker container to, and then to provide it as follows:

    <container type="docker"></container>

Then, you should be able to run it with:

planemo test --docker bwa-mem.xml