code: public VisDialog button (String text, Object object) {
  		if (skin == null)
  			throw new IllegalStateException("This method may only be used if the dialog was constructed with a Skin.");
  		return button(text, object, skin.get(VisTextButtonStyle.class));
  	}
docs: Adds a text button to the button table. The dialog must have been constructed with a skin to use this method.
  @param object The object that will be passed to {@link #result(Object)} if this button is clicked. May be null.