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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 success(self):
 """ Checks for the presence of errors in the response. Returns ``True`` if all is well, ``False`` otherwise. :rtype: bool :returns ``True`` if PayPal says our query was successful. """

        return self.ack.upper() in (self.config.ACK_SUCCESS,
                                    self.config.ACK_SUCCESS_WITH_WARNING)