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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(self, username):
 """ If using the remember option and KitsuAuth is storing your tokens, this function will retrieve one. :param username: The username whose token we are retrieving :return: A token, NotFound or NotSaving error """

        if not self.remember:
            raise NotSaving

        if username not in self.token_storage:
            raise UserNotFound

        if self.token_storage[username]['expiration'] < time.time():
            new_token = self.refresh(self.token_storage[username]['refresh'])
            self.token_storage[username]['token'] = new_token[0]
            self.token_storage[username]['expiration'] = new_token[1]
            return new_token[0]
        else:
            return self.token_storage[username]['token']