Why does @property and @classmethod not work the same in Python 2.7 appengine-rest-server
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I have been using Python 2.5 with appengine-rest-server

I used @property and @classmethod to add computed properties to the returned data in this way

class User(db.Model):

    userName = db.StringProperty(required=True)
    ...

    @property
    def userThumb(self):
        thumbUrl = ''
        images = self.user_images #a reference property to user images entity
        if images:
            images.filter('defaultThumb =', True)
            result = images.get()
            if result:
                thumbUrl = result.userThmbUrl
            
            return thumbUrl

    @classmethod
    def restProps(cls):
        result = cls.properties()
        result.update({"userThumb": db.StringProperty()})
        return result

This would add the userThumb (a url) field to the rest response

However, this code does not work anymore in Python 2.7
Are there any ideas why?