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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 response_url(self):
 """ Returns remapped lis_outcome_service_url uses PYLTI_URL_FIX map to support edX dev-stack :return: remapped lis_outcome_service_url """

        url = ""
        url = self.session['lis_outcome_service_url']
        app_config = self.lti_kwargs['app'].config
        urls = app_config.get('PYLTI_URL_FIX', dict())
        # url remapping is useful for using devstack
        # devstack reports httpS://localhost:8000/ and listens on HTTP
        for prefix, mapping in urls.items():
            if url.startswith(prefix):
                for _from, _to in mapping.items():
                    url = url.replace(_from, _to)
        return url