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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(self, permission_id, expand=[]):
 """ List a specific permisison for the given object. :param str permission_id: the id of the Permission to be listed. """

        parent_url = self.client.get_url(self.parent_object._manager._URL_KEY, 'GET', 'single', {'id': self.parent_object.id})
        target_url = parent_url + self.client.get_url_path(
            self._URL_KEY, 'GET', 'single', {'permission_id': permission_id})
        return self._get(target_url, expand=expand)