code: def univec(self, databasepath):
          
          logging.info('Downloading univec database')
          databasepath = self.create_database_folder(databasepath, 'univec')
          # Set the name of the output file
          outputfile = os.path.join(databasepath, 'UniVec_core.tfa')
          target_url = 'ftp://ftp.ncbi.nlm.nih.gov/pub/UniVec/UniVec_Core'
          self.database_download(output_file=outputfile,
                                 target_url=target_url,
                                 database_path=databasepath)
          # Create a copy of the file with a .fasta extension
          if os.path.isfile(outputfile):
              renamed = os.path.splitext(outputfile)[0] + '.fasta'
              shutil.copy(outputfile, renamed)
docs: Download the UniVec core database
          :param databasepath: path to use to save the database