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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 add_whitelist_entry(self, address, netmask, note=None):
 """ Adds a new entry to this user's IP whitelist, if enabled """

        result = self._client.post("{}/whitelist".format(Profile.api_endpoint),
                data={
                    "address": address,
                    "netmask": netmask,
                    "note": note,
        })

        if not 'id' in result:
            raise UnexpectedResponseError("Unexpected response creating whitelist entry!")

        return WhitelistEntry(result['id'], self._client, json=result)