code: def _GetEarliestYearFromFileEntry(self):
      
      file_entry = self.GetFileEntry()
      if not file_entry:
        return None
  
      stat_object = file_entry.GetStat()
  
      posix_time = getattr(stat_object, 'crtime', None)
      if posix_time is None:
        posix_time = getattr(stat_object, 'ctime', None)
  
      # Gzip files don't store the creation or metadata modification times,
      # but the modification time stored in the file is a good proxy.
      if file_entry.TYPE_INDICATOR == dfvfs_definitions.TYPE_INDICATOR_GZIP:
        posix_time = getattr(stat_object, 'mtime', None)
  
      if posix_time is None:
        logger.warning(
            'Unable to determine earliest year from file stat information.')
        return None
  
      try:
        year = timelib.GetYearFromPosixTime(
            posix_time, timezone=self._knowledge_base.timezone)
        return year
      except ValueError as exception:
        logger.error((
            'Unable to determine earliest year from file stat information with '
            'error: {0!s}').format(exception))
        return None
docs: Retrieves the year from the file entry date and time values.
  
      This function uses the creation time if available otherwise the change
      time (metadata last modification time) is used.
  
      Returns:
        int: year of the file entry or None.