docs: def check_lazy_load_gewest(f):
      '''
      Decorator function to lazy load a :class:`Gewest`.
      '''
      def wrapper(self):
          gewest = self
          attribute = 'namen' if f.__name__ == 'naam' else f.__name__
          if (getattr(gewest, '_%s' % attribute, None) is None):
              log.debug('Lazy loading Gewest %d', gewest.id)
              gewest.check_gateway()
              g = gewest.gateway.get_gewest_by_id(gewest.id)
              gewest._namen = g._namen
              gewest._centroid = g._centroid
              gewest._bounding_box = g._bounding_box
          return f(self)
      return wrapper