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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 GetJson(self):
 """Returns JSON version of ClientData compatible with FIDO spec."""


    # The U2F Raw Messages specification specifies that the challenge is encoded
    # with URL safe Base64 without padding encoding specified in RFC 4648.
    # Python does not natively support a paddingless encoding, so we simply
    # remove the padding from the end of the string.
    server_challenge_b64 = base64.urlsafe_b64encode(
        self.raw_server_challenge).decode()
    server_challenge_b64 = server_challenge_b64.rstrip('=')
    return json.dumps({'typ': self.typ,
                       'challenge': server_challenge_b64,
                       'origin': self.origin}, sort_keys=True)