ToggleGroup 0.5 API

```
public class ToggleGroup

                    
```
A ToggleGroup may be set as an attribute in ToggleButton or RadioButton.
All Buttons that keep the same instance of a ToggleGroup belong to that ToggleGroup. Only one Button may be selected in a ToggleGroup. This means whenever a Button changes its selected state to true, all other Buttons in the same ToggleGroup get deselected.
An exception to this rule is, whenever a new ToggleButton or RadioButton that is currently selected gets added to the ToggleGroup.

Constructor Summary

Constructors
Constructor	Description
`ToggleGroup()`	Creates a ToggleGroup.

- Constructor Detail
  - ToggleGroup
```
ToggleGroup()
```
    Creates a ToggleGroup.