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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_feedback(self, feedbacktype="comments", folderid="", stack=1, offset=0, limit=10):
 """Fetch feedback messages :param feedbacktype: Type of feedback messages to fetch (comments/replies/activity) :param folderid: The folder to fetch messages from, defaults to inbox :param stack: True to use stacked mode, false to use flat mode :param offset: the pagination offset :param limit: the pagination limit """


        if self.standard_grant_type is not "authorization_code":
            raise DeviantartError("Authentication through Authorization Code (Grant Type) is required in order to connect to this endpoint.")

        response = self._req('/messages/feedback', {
            'type' : feedbacktype,
            'folderid' : folderid,
            'stack' : stack,
            'offset' : offset,
            'limit' : limit
        })

        messages = []

        for item in response['results']:

            m = Message()
            m.from_dict(item)

            messages.append(m)

        return {
            "results" : messages,
            "has_more" : response['has_more'],
            "next_offset" : response['next_offset']
        }