def use_ssh_tunnel(self):
        required = [
            'ssh_key_file',
            'ssh_tunnel',
            'ssh_tunnel_port',
            'ssh_remote_host',
            'ssh_remote_port',
        ]

        has = len(filter(lambda x: self.get(x) is not None, required))
        if has > 0 and has != len(required):
            self._logger.warning('Missing {0} of {1} required config variables for ssh'.format(has - len(required), len(required)))

        return has == len(required)
dataset/ETHPy150Open python-beaver/python-beaver/beaver/config.py/BeaverConfig.use_ssh_tunnel/swapped operands of `-`