docs: protected E getSelectedEnumFromRadioButtons()
  	{
  		for (final E enumValue : this.radioButtonMap.keySet())
  		{
  			final JRadioButton btn = this.radioButtonMap.get(enumValue);
  			if (btn.isSelected())
  			{
  				return enumValue;
  			}
  		}
  		return null;
  	}