def yaml(self):
        return yaml.dump(self.serialized, default_flow_style=False,
                         encoding=None)
def main(self):
      UI.OpenDialog(
        VBox(
          Heading("This Is a Heading."),
          Label("This is a Label."),
          PushButton("&OK")
        )
      )
      UI.UserInput()
      UI.CloseDialog()