code: def convert_to_string(self, block):
          
          out = ""
          for seq_record in block:
              taxon_id = ">{0}_{1}_{2} [org={0} {1}] [Specimen-voucher={2}] " \
                         "[note={3} gene, partial cds.] [Lineage={4}]".format(
                  seq_record.taxonomy['genus'],
                  seq_record.taxonomy['species'],
                  seq_record.voucher_code,
                  seq_record.gene_code,
                  seq_record.lineage,
              )
              sequence = get_seq(seq_record, self.codon_positions, self.aminoacids,
                                 self.degenerate)
              seq = sequence.seq
              if sequence.warning:
                  self.warnings.append(sequence.warning)
  
              n = 60
              seq = [seq[i:i + n] for i in range(0, len(seq), n)]
              out += '{0}\n{1}\n'.format(taxon_id, "\n".join(seq))
          return out
docs: Takes a list of SeqRecordExpanded objects corresponding to a gene_code
          and produces the gene_block as string.
  
          :param block:
          :return: str.