def _get_asset_size(self, asset_type):
        """
        Helper function to dynamically create *_size properties.
        """
        if asset_type == 'page':
            assets = self.entries
        else:
            assets = getattr(self, '{0}_files'.format(asset_type), None)
        return self.get_total_size(assets)
Helper function to dynamically create *_size properties.