code: def update_http_rules(rules, content_type='text/plain'):
      
      for kw in deepcopy(rules):
  
          kw['url'] = re.compile(kw['url'])
  
          # ensure headers dict for at least have a default content type
          if 'Content-Type' not in kw.get('headers', {}):
              kw['headers'] = dict(kw.get('headers', {}), **{
                  'Content-Type': content_type,
              })
  
          method = kw.pop('method')
          url = kw.pop('url')
  
          http_mock.register_uri(method, url, **kw)
docs: Adds rules to global http mock.
  
      It permits to set mock in a more global way than decorators, cf.:
      https://github.com/openstack/requests-mock
  
      Here we assume urls in the passed dict are regex we recompile before adding
      a rule.
  
      Rules example:
  
      >>> def fake_duckduckgo_cb(request):
      ...     return 200, {}, 'Coincoin!'
  
      >>> rules = [
          {
              'method': 'GET',
              'status_code': 200,
              'text': 'I am watching you',
              'url': r'^https://www.google.com/#q='
          },
          {
              'method': 'GET',
              'text': fake_duckduckgo_cb,
              'url': r'^https://duckduckgo.com/?q='
          },
      ]