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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 _refresh(self):
 """Refresh the API token using the currently bound credentials. This is simply a convenience method to be invoked automatically if authentication fails during normal client use. """

        # Request and set a new API token.
        new_token = self.authenticate(self._username, self._password)
        self._token = new_token
        logger.info('New API token received: "{}".'.format(new_token))
        return self._token