'``kwargs`` supplied to ``command`` can be serialized and unserialized.'

def assert_roundtrips(self, command, **kwargs):

    amp_protocol = None
    argument_box = command.makeArguments(kwargs, amp_protocol)
    [roundtripped] = parseString(argument_box.serialize())
    parsed_objects = command.parseArguments(roundtripped, amp_protocol)
    self.assertEqual(kwargs, parsed_objects)
