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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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