'Determine which file maps to which piece ranges for progress info'

def set_filepieceranges(self):

    self._logger.debug('LibtorrentDownloadImpl:    set_filepieceranges:    %s', self.get_selected_files())
    metainfo = self.tdef.get_metainfo()
    self.filepieceranges = maketorrent.get_length_filepieceranges_from_metainfo(metainfo, [])[1]
