Enter into configuration mode on remote device.

        Cisco IOS devices abbreviate the prompt at 20 chars in config mode

def config_mode(self, config_command="config term", pattern=""):
        """
        Enter into configuration mode on remote device.

        Cisco IOS devices abbreviate the prompt at 20 chars in config mode
        """
        if not pattern:
            pattern = re.escape(self.base_prompt[:16])
        return super(CiscoBaseConnection, self).config_mode(
            config_command=config_command, pattern=pattern
        )