def __call__(self, parser, namespace, values, option_string=None):
if values == "<STR_LIT>":<EOL><INDENT>setattr(namespace, self.dest, const.PROTOCOL_MRP)<EOL><DEDENT>elif values == "<STR_LIT>":<EOL><INDENT>setattr(namespace, self.dest, const.PROTOCOL_DMAP)<EOL><DEDENT>else:<EOL><INDENT>raise ArgumentTypeError('<STR_LIT>')<EOL><DEDENT>
Match protocol string and save correct version.