code: def get_header_dict(response, header):
      
      def dictitem(s):
          t = s.split('=', 1)
          if len(t) > 1:
              return (t[0].lower(), t[1])
          else:
              return (t[0].lower(), True)
  
      if response.has_header(header):
          hd = dict([dictitem(el) for el in cc_delim_re.split(response[header])])
      else:
          hd= {}
      return hd
docs: returns a dictionary of the cache control headers
          the same as is used by django.utils.cache.patch_cache_control
          if there are no Cache-Control headers returns and empty dict