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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 update(self, status, source=None, params={}):
        "Update your status.  Returns the ID of the new post."
        params = params.copy()
        params['status'] = status
        if source:
            params['source'] = source
        return self.__parsed_post(self.__post('/statuses/update.xml', params),
            txml.parseUpdateResponse)