code: def _incorporate_dup(self):
          
          seq, cds_start, cds_stop, start, end = self._setup_incorporate()
  
          dup_seq = seq[start:end]
          seq[end:end] = dup_seq
  
          is_frameshift = len(dup_seq) % 3 != 0
          variant_start_aa = int(math.ceil((self._var_c.posedit.pos.end.base + 1) / 3.0))
  
          alt_data = AltTranscriptData(
              seq,
              cds_start,
              cds_stop,
              is_frameshift,
              variant_start_aa,
              self._transcript_data.protein_accession,
              is_ambiguous=self._ref_has_multiple_stops)
          return alt_data
docs: Incorporate dup into sequence