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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 ValidateFeedStartAndExpirationDates(self, problems, first_date, last_date, first_date_origin, last_date_origin, today):
 """Validate the start and expiration dates of the feed. Issue a warning if it only starts in the future, or if it expires within 60 days. Args: problems: The problem reporter object first_date: A date object representing the first day the feed is active last_date: A date object representing the last day the feed is active today: A date object representing the date the validation is being run on Returns: None """

    warning_cutoff = today + datetime.timedelta(days=60)
    if last_date < warning_cutoff:
        problems.ExpirationDate(time.mktime(last_date.timetuple()),
                                last_date_origin)

    if first_date > today:
      problems.FutureService(time.mktime(first_date.timetuple()),
                             first_date_origin)