I thougth of this when writing the patch.
But because of this test beyoud, I don't implement the patch this way.
```
$tester->run(array('command' => 'list', '--verbose' => 4));
$this->assertSame(Output::VERBOSITY_VERBOSE, $tester->getOutput()->getVerbosity(), '->run() sets the output to verbose if unknown --verbose level is passed');
```
Will do this and fix the above test if you're ok with it.