JavaFX RadioButton (Swing)

import javafx.ext.swing.SwingToggleGroup;
import javafx.ext.swing.SwingRadioButton;

//A toggle group to switch between radio buttons
var toggleGroup = SwingToggleGroup{};

//Radio buttons
var radioButton1 = SwingRadioButton{
  text: "Green" 
  foreground: Color.SEAGREEN 
  toggleGroup: toggleGroup
};
var radioButton2 = SwingRadioButton{
  text: "Red" 
  foreground: Color.RED 
  toggleGroup: toggleGroup
};
var radioButton3 = SwingRadioButton{
  text: "Blue" 
  foreground: Color.BLUE 
  toggleGroup: toggleGroup
};