code: def _GetParentModificationTime(self, gzip_file_entry):
      
      parent_file_entry = path_spec_resolver.Resolver.OpenFileEntry(
          gzip_file_entry.path_spec.parent)
      if not parent_file_entry:
        return None
  
      return parent_file_entry.modification_time
docs: Retrieves the modification time of the file entry's parent file.
  
      Note that this retrieves the time from the file entry of the parent of the
      gzip file entry's path spec, which is different from trying to retrieve it
      from the gzip file entry's parent file entry.
  
      It would be preferable to retrieve the modification time from the metadata
      in the gzip file itself, but it appears to not be set when the file is
      written by fseventsd.
  
      Args:
        gzip_file_entry (dfvfs.FileEntry): file entry of the gzip file containing
            the fseventsd data.
  
      Returns:
        dfdatetime.DateTimeValues: parent modification time, or None if not
            available.