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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 ratelimit_remaining(self):
 """Number of requests before GitHub imposes a ratelimit. :returns: int """

        json = self._json(self._get(self._github_url + '/rate_limit'), 200)
        core = json.get('resources', {}).get('core', {})
        self._remaining = core.get('remaining', 0)
        return self._remaining