code: def to_native(self, value):
          
          if isinstance(value, six.string_types):
              value_list = value.split(self.string_delim)
          else:
              value_list = value
  
          to_native = self.member_type.to_native if self.member_type is not None else lambda x: x
          return [to_native(item) for item in value_list]
docs: Load a value as a list, converting items if necessary