docs: def as_list(self):
          """Returns GO annotation as a flat list (in GAF 2.1 format order)."""
          go_id = self.go_term.id
          
          qual_str = '|'.join(self.qualifier)
          db_ref_str = '|'.join(self.db_ref)
          taxon_str = '|'.join(self.taxon)
  
          # with_from is currently left as a string
          # with_from = '|'.join()
          with_from_str = self.with_from or ''
          db_name_str = self.db_name or ''
          db_syn_str = '|'.join(self.db_syn)
          ext_str = '|'.join(self.ext)
          product_id_str = self.product_id or ''
  
          l = [
              self.db,
              self.db_id,
              self.db_symbol,
              qual_str,
              go_id,
              db_ref_str,
              self.ev_code,
              with_from_str,
              self.aspect,
              db_name_str,
              db_syn_str,
              self.db_type,
              taxon_str,
              self.date,
              self.assigned_by,
              ext_str,
              product_id_str,
          ]
          return l