code: def _get_stringlist_from_commastring(self, field):
          # type: (str) -> List[str]
          
          strings = self.data.get(field)
          if strings:
              return strings.split(',')
          else:
              return list()
docs: Return list of strings from comma separated list
  
          Args:
              field (str): Field containing comma separated list
  
          Returns:
              List[str]: List of strings