<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _cfg_exists(self, cfg_str):
 """Check a partial config string exists in the running config. :param cfg_str: config string to check :return : True or False """

        ios_cfg = self._get_running_config()
        parse = HTParser(ios_cfg)
        cfg_raw = parse.find_lines("^" + cfg_str)
        LOG.debug("_cfg_exists(): Found lines %s", cfg_raw)
        return len(cfg_raw) > 0