docs: def write_tsv(self, path):
          """Write the database to a tab-delimited text file.
  
          Parameters
          ----------
          path: str
              The path name of the file.
  
          Returns
          -------
          None
          """
          with open(path, 'wb') as ofh:
              writer = csv.writer(
                  ofh, dialect='excel-tab',
                  quoting=csv.QUOTE_NONE, lineterminator=os.linesep
              )
              for gs in self._gene_sets.values():
                  writer.writerow(gs.to_list())