def access_key(self, data):
        """
        Set a new access code which will be required for future re-programmings of your YubiKey.

        Supply data as either a raw string, or a hexlified string prefixed by 'h:'.
        The result, after any hex decoding, must be 6 bytes.
        """
        if data.startswith(b'h:'):
            new = binascii.unhexlify(data[2:])
        else:
            new = data
        if len(new) == 6:
            self.access_code = new
        else:
            raise yubico_exception.InputError('Access key must be exactly 6 bytes')
Set a new access code which will be required for future re-programmings of your YubiKey.

        Supply data as either a raw string, or a hexlified string prefixed by 'h:'.
        The result, after any hex decoding, must be 6 bytes.