code: def _generate_union_properties(self, fields):
          
          for field in fields:
              # void types do not need properties to store additional state
              # information
              if not is_void_type(field.data_type):
                  doc = self.process_doc(
                      field.doc, self._docf) if field.doc else undocumented
                  warning_str = (
                      ' @note Ensure the `is{}` method returns true before accessing, '
                      'otherwise a runtime exception will be raised.')
                  doc += warning_str.format(fmt_camel_upper(field.name))
                  self.emit_wrapped_text(
                      self.process_doc(doc, self._docf), prefix=comment_prefix)
                  self.emit(fmt_property(field=field))
                  self.emit()
docs: Emits union instance properties from the given fields.