def __get__(self, instance, owner):
        arg = instance.arguments[self.name]
        try:
            value = instance.__dict__[arg.name]
        except __HOLE__:
            raise AttributeError(self.name)
        key = hash(instance)
        if data.instance_stack[key]:
            instance = data.instance_stack[key][-1]
            if arg.resolve_field and hasattr(value, 'resolve'):
                value = value.resolve(instance)
            elif hasattr(value, '__call__'):
                value = value(instance)
        return value
dataset/ETHPy150Open gulopine/steel/steel/common/args.py/Argument.__get__