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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_areas(self):
 """ Return surface elements area values in a numpy array. """

        if self.areas is None:
            self.areas = []
            for surf in self.surfaces:
                self.areas.append(surf.get_area())
            self.areas = numpy.array(self.areas)

        return self.areas