code: def total_core(self):
          
          corefile = os.path.join(self.reffilepath, self.analysistype, 'Escherichia', 'core_combined.fasta')
          for record in SeqIO.parse(corefile, 'fasta'):
              gene_name = record.id.split('-')[0]
              if gene_name not in self.coregenomes:
                  self.coregenomes.append(gene_name)
docs: Determine the total number of core genes present