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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 send_message(self, to_number, message, from_number=None):
 """ Send a message to the specified number and return a response dictionary. The numbers must be specified in international format starting with a '+'. Returns a dictionary that contains a 'MessageId' key with the sent message id value or contains 'errorCode' and 'message' on error. Possible error codes: 40001 - Parameter validation 40002 - Missing parameter 40003 - Invalid request 40100 - Illegal authorization header 40200 - There is not enough funds to send the message 40300 - Forbidden request 40301 - Invalid authorization scheme for calling the method 50000 - Internal error """


        values = {'Message': message}
        if from_number is not None:
            values['From'] = from_number

        return self._request(self.SEND_SMS_URL + to_number, values)