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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 parse_challenge_message(self, msg2):
 """ Parse the NTLM CHALLENGE_MESSAGE from the server and add it to the Ntlm context fields :param msg2: A base64 encoded string of the CHALLENGE_MESSAGE """

        msg2 = base64.b64decode(msg2)
        self.challenge_message = ChallengeMessage(msg2)