code: def get_urls_and_locations(self, urls):
          
          location_generator = self.get_new_locations(urls)
          initial_cache = list(set(urls))
          return CachedIterable(location_generator, initial_cache)
docs: Get URLs and their redirection addresses.
  
          :param urls: a list of URL addresses
          :returns: an instance of CachedIterable containing given URLs
          and valid location header values of their responses