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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 delete_repo(self, auth, username, repo_name):
 """ Deletes the repository with name ``repo_name`` owned by the user with username ``username``. :param auth.Authentication auth: authentication object :param str username: username of owner of repository to delete :param str repo_name: name of repository to delete :raises NetworkFailure: if there is an error communicating with the server :raises ApiFailure: if the request cannot be serviced """

        path = "/repos/{u}/{r}".format(u=username, r=repo_name)
        self.delete(path, auth=auth)