code: def _save_cache(self):
          
          # Create the cache directory
          safe_makedirs(self.cache_dir)
  
          # Create/overwrite the cache file
          try:
              with open(self.cache_file, 'wb') as f:
                  pickle.dump(self.data, f)
          except Exception as e:
              logger.error("Cannot write version to cache file {} ({})".format(self.cache_file, e))
docs: Save data to the cache file.