Sets the status message on the *last* commit for this pull request
        to be 'pending' with a details link to a newly created Wiki page with
        the setup of the unit tests being run. Does *not* run the actual unit
        tests yet.

def begin(self):
        """Sets the status message on the *last* commit for this pull request
        to be 'pending' with a details link to a newly created Wiki page with
        the setup of the unit tests being run. Does *not* run the actual unit
        tests yet.
        """
        self.url = self.server.wiki.create(self)
        if not self.testmode:
            self.commit.create_status("pending", self.url, "Running unit tests...")