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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 _create_ssh_keys(self):
 """ Generate a pair of ssh keys for this prefix Returns: None Raises: RuntimeError: if it fails to create the keys """

        ret, _, _ = utils.run_command(
            [
                'ssh-keygen',
                '-t',
                'rsa',
                '-m',
                'PEM',
                '-N',
                '',
                '-f',
                self.paths.ssh_id_rsa(),
            ]
        )
        if ret != 0:
            raise RuntimeError(
                'Failed to crate ssh keys at %s',
                self.paths.ssh_id_rsa(),
            )