So what I figured out when using the `pep8` linter is that `message` is actually a `list` instead of `string`. I imagined that this is intended, as linters may have more than one message line. GitHub was also happy to accept a list as a comment.

So, this function iterates through this `message` list and removes any duplicate sub-messages, returning a `list` again with only new messages.

What you suggest, `comment['body'] == message` would compare a list to a string and therefore would not work, unless I'm missing something.