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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 daylight_utc(self, date, latitude, longitude, observer_elevation=0):
 """Calculate daylight start and end times in the UTC timezone. :param date: Date to calculate for. :type date: :class:`datetime.date` :param latitude: Latitude - Northern latitudes should be positive :type latitude: float :param longitude: Longitude - Eastern longitudes should be positive :type longitude: float :param observer_elevation: Elevation in metres to calculate daylight for :type observer_elevation: int :return: A tuple of the UTC date and time at which daylight starts and ends. :rtype: (:class:`~datetime.datetime`, :class:`~datetime.datetime`) """


        start = self.sunrise_utc(date, latitude, longitude, observer_elevation)
        end = self.sunset_utc(date, latitude, longitude, observer_elevation)

        return start, end