def _handle_job_set(function):
    """A decorator for handling `taskhandle.JobSet`\s

    A decorator for handling `taskhandle.JobSet`\s for `do` and `undo`
    methods of `Change`\s.
    """
    def call(self, job_set=taskhandle.NullJobSet()):
        job_set.started_job(str(self))
        function(self)
        job_set.finished_job()
    return call