def __init__(self):
        super(Compare, self).__init__()
        self._init_create()

    def _init_create(self):
        def expected_parser_received_exception(expected, actual):
            self.fail(msg='%s: expected parser, but received exception: %s' % (self.name, actual))
        def expected_exception_received_parser(expected, actual):
            self.fail(msg='%s: ')
        def both_exception(expected, actual):
            self.assertEquals(expected = actual, msg="expected exception '%s', but received '%s'" % (expected, actual))
        self._create = {}
        self._create[('PARSER', 'PARSER')] = self.parse_args
        self._create[('PARSER', 'EXCEPTION')] = expected_parser_received_exception
        self._create[('EXCEPTION', 'PARSER')] = expected_exception_received_parser
        self._create[('EXCEPTION', 'EXCEPTION')] = both_exception


    def check_parser(self, expected, actual):
        def create_parser(self, callback):
            try:
                result = callback()
                return 'PARSER', result
            with BaseException, e:
                return 'EXCEPTION', repr(e)
        expected_kind, expected_result = create_parser(expected)
        actual_kind, actual_result  = create_parser(actual)
        self._create[(expected_kind, actual_kind)](expected_result, actual_result)