src/transformers/models/marian/convert_marian_tatoeba_to_pytorch.py/TatoebaConverter/get_tags
class TatoebaConverter:    def get_tags(self, code, name):
        if len(code) == 2:
            assert "languages" not in name, f"{code}: {name}"
            return [code]
        elif self.is_group(code, name):
            group = self.expand_group_to_two_letter_codes(code)
            group.append(code)
            return group
        else:  # zho-> zh
            print(f"Three letter monolingual code: {code}")
            return [code]