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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 _to_utc(self, dt):
 """Takes a naive timezone with an localized value and return it formatted as utc."""

        tz = self._get_tz()
        loc_dt = tz.localize(dt)
        return loc_dt.astimezone(pytz.utc)