Code review comment for lp:~sinzui/juju-release-tools/validate-streams

I am finding it very hard to understand check_expected_tools. I don't know why it will accept version and then basically ignore it if retracted is set. It seems like retracted is really a mode, not a parameter. I would like to see a test like this:

old_tools = make_tools_data('trusty', 'amd64', ['1.20.7', '1.20.9'])
new_tools = make_tools_data('trusty', 'amd64', ['1.20.7', '1.20.8'])
check_expected_tools(old_tools, new_tools, '1.20.8', '1.20.9')

Notice that 1.20.8 has been added and 1.20.9 has been removed. I don't know what the expected behaviour is. I think the actual behaviour is that it will complain that 1.20.8 is unexpected.