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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 get_expiration(self):
 """Returns the expiration date. :returns: expiration date :rtype: datetime object """

        exp = self._get_int('expiration')
        if exp is not None:
            return datetime.datetime.fromtimestamp(
                exp
            )
        return None