Get :class:`Collection` instance.
        
        :param key: object_key or object_name
        :param using_name: True if getting object by object name

def get_collection(self, key, using_name=True):
        """Get :class:`Collection` instance.
        
        :param key: object_key or object_name
        :param using_name: True if getting object by object name
        """
        object_ = self.application.get_object(key, using_name=using_name)
        collection = Collection.from_dict(object_.__dict__)
        for http_cmd in ["get", "post", "put", "delete"]:
            collection.__setattr__(http_cmd, self.auth.__getattribute__(http_cmd))
        return collection