code: def _ValidateCacheEntryHeader(self, cache_entry_header):
      
      return (
          cache_entry_header.request_size > 0 and
          cache_entry_header.request_size < self._MAXIMUM_URL_LENGTH and
          cache_entry_header.major_format_version == 1 and
          cache_entry_header.last_fetched_time > 0 and
          cache_entry_header.fetch_count > 0)
docs: Determines whether the values in the cache entry header are valid.
  
      Args:
        cache_entry_header (firefox_cache1_entry_header): cache entry header.
  
      Returns:
        bool: True if the cache entry header is valid.