code: def _load_github_hooks(github_url='https://api.github.com'):
      
      try:
          resp = requests.get(github_url + '/meta')
          if resp.status_code == 200:
              return resp.json()['hooks']
          else:
              if resp.headers.get('X-RateLimit-Remaining') == '0':
                  reset_ts = int(resp.headers['X-RateLimit-Reset'])
                  reset_string = time.strftime('%a, %d %b %Y %H:%M:%S GMT',
                                               time.gmtime(reset_ts))
                  raise ServiceUnavailable('Rate limited from GitHub until ' +
                                           reset_string)
              else:
                  raise ServiceUnavailable('Error reaching GitHub')
      except (KeyError, ValueError, requests.exceptions.ConnectionError):
          raise ServiceUnavailable('Error reaching GitHub')
docs: Request GitHub's IP block from their API.
  
      Return the IP network.
  
      If we detect a rate-limit error, raise an error message stating when
      the rate limit will reset.
  
      If something else goes wrong, raise a generic 503.