code: def add_alt(self, entry):
          
          entry = entry[7:-1]
          info = entry.split(',')
          if len(info) < 2:
              return False
          for v in info:
              key, value = v.split('=', 1)
              if key == 'ID':
                  self.alt[value] = {}
                  id_ = value
              elif key == 'Description':
                  self.alt[id_]['description'] = value
                  if len(info) > 4:
                      self.alt[id_]['description'] += '; '.join(info[4:])
                  break
          return True
docs: Parse and store the alternative allele field