code: def _generate_union_class_symbol_creators(self, data_type):
          
          class_name = fmt_class(data_type.name)
          lineno = self.lineno
          for field in data_type.fields:
              if is_void_type(field.data_type):
                  field_name = fmt_func(field.name)
                  self.emit("{0}.{1} = {0}('{1}')".format(class_name, field_name))
          if lineno != self.lineno:
              self.emit()
docs: Class attributes that represent a symbol are set after the union class
          definition.