code: def patch_headers(self, response):
          
  
          # Remove Vary:Cookie if we want to cache non-anonymous
          if not getattr(settings, 'BETTERCACHE_ANONYMOUS_ONLY', False):
              vdict = get_header_dict(response, 'Vary')
              try:
                  vdict.pop('cookie')
              except KeyError:
                  pass
              else:
                  set_header_dict(response, 'Vary', vdict)
  
          #  Set max-age, post-check and pre-check
          cc_headers = get_header_dict(response, 'Cache-Control')
          try:
              timeout = cc_headers['max-age']
          except KeyError:
              timeout = settings.BETTERCACHE_CACHE_MAXAGE
              cc_headers['max-age'] = timeout
          # This should never happen but let's be safe
          if timeout is 0:
              return response
          if not 'pre-check' in cc_headers:
             cc_headers['pre-check'] = timeout
          if not 'post-check' in cc_headers:
             cc_headers['post-check'] = int(timeout * settings.BETTERCACHE_EDGE_POSTCHECK_RATIO)
          set_header_dict(response, 'Cache-Control', cc_headers)
          # this should be the main/first place we're setting edge control so we can just set what we want
          ec_dict = {'cache-maxage' : settings.BETTERCACHE_EDGE_MAXAGE}
          set_header_dict(response, 'Edge-Control', ec_dict)
          response['Last-Modified'] = http_date()
          return response
docs: Set the headers we want for caching.