[galaxy-dev] Ignoring white space differences in test output

Hi all, I'd like to write a tool test where the sample output and the generated output are the same except for white space. i.e. running diff with the -w switch reports no differences. Is this possible at the moment with the Galaxy test framework? I'm hoping for a <test> <output> attribute. I don't see anything like this mentioned here: https://bitbucket.org/galaxy/galaxy-central/wiki/WritingTests Thanks, Peter