Saves the startup-config and private-config to files.

def save_configs(self):
        """
        Saves the startup-config and private-config to files.
        """

        if self.startup_config_content or self.private_config_content:
            startup_config_content, private_config_content = self.extract_configs()
            if startup_config_content:
                config_path = os.path.join(self.working_dir, "startup-config.cfg")
                try:
                    config = startup_config_content.decode("utf-8", errors="replace")
                    with open(config_path, "wb") as f:
                        log.info("saving startup-config to {}".format(config_path))
                        f.write(config.encode("utf-8"))
                except (binascii.Error, OSError) as e:
                    raise IOUError("Could not save the startup configuration {}: {}".format(config_path, e))

            if private_config_content and private_config_content != b'\nend\n':
                config_path = os.path.join(self.working_dir, "private-config.cfg")
                try:
                    config = private_config_content.decode("utf-8", errors="replace")
                    with open(config_path, "wb") as f:
                        log.info("saving private-config to {}".format(config_path))
                        f.write(config.encode("utf-8"))
                except (binascii.Error, OSError) as e:
                    raise IOUError("Could not save the private configuration {}: {}".format(config_path, e))