def ValidateServiceExceptions(self,
                                problems,
                                first_service_day,
                                last_service_day):
    # good enough approximation
    six_months = datetime.timedelta(days=182)
    service_span = last_service_day - first_service_day
    if service_span < six_months:
      # We don't check for exceptions because the feed is
      # active for less than six months
      return

    for period in self.GetServicePeriodList():
      # If at least one ServicePeriod has service exceptions we don't issue the
      # warning, so we can stop looking at the list of ServicePeriods.
      if period.HasExceptions():
        return
    problems.NoServiceExceptions(start=first_service_day,
                                 end=last_service_day)
dataset/ETHPy150Open google/transitfeed/transitfeed/schedule.py/Schedule.ValidateServiceExceptions/original