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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 _get_access_token(self, code, **params):
 """ Fetch an access token with the provided `code`. """

        params.update({
            'code': code,
            'client_id': self.client_id,
            'client_secret': self.secret,
            'redirect_uri': self.get_callback_url(),
        })

        logger.debug("Params: %s", params)

        resp, content = self.request_access_token(params=params)

        content = smart_unicode(content)

        logger.debug("Status: %s", resp['status'])
        logger.debug("Content: %s", content)
        
        content = self.parse_access_token(content)
        
        if 'error' in content:
            raise OAuthError(_(
                u"Received error while obtaining access token from %s: %s") % (
                    self.access_token_url, content['error']))

        return content