docs: def _add_hgnc_symbols(self, variant_obj):
          """Add hgnc symbols to the variant
          
              If there are transcripts use the symbols found here,
              otherwise use phizz to get the gene ids.
          """
          hgnc_symbols = set()
          if variant_obj.transcripts:
              for transcript in variant_obj.transcripts:
                  if transcript.hgnc_symbol:
                      hgnc_symbols.add(transcript.hgnc_symbol)
          else:
              chrom = variant_obj.CHROM
              start = variant_obj.start
              stop = variant_obj.stop
          
              hgnc_symbols = get_gene_symbols(chrom, start, stop)
          #Make unique ids
          variant_obj.gene_symbols = list(hgnc_symbols)