docs: def _get_genes(self, variant):
          """Add the genes for a variant
  
          Get the hgnc symbols from all transcripts and add them
          to the variant
  
          Args:
              variant (dict): A variant dictionary
  
          Returns:
              genes (list): A list of Genes
          """
          ensembl_ids = []
          hgnc_symbols = []
          
          for transcript in variant.transcripts:
              if transcript.ensembl_id:
                  ensembl_ids.append(transcript.ensembl_id)
              if transcript.hgnc_symbol:
                  hgnc_symbols.append(transcript.hgnc_symbol)
          
          genes = get_gene_info(
                          ensembl_ids=ensembl_ids, 
                          hgnc_symbols=hgnc_symbols
                          )
          return genes