[ToggleGroup] Problem with bidirectional binding

Launch attached application.

Explanation: first two check boxes just show state of two toggle buttons "Selected property"
Second two check boxes are used to set values to the same Selected properties.

You can put toggle buttons and get them out of group using toggle button "state: grouped/ungrouped"
You can bind second two scheck boxes using toggle button "state: binded/unbinded"

For testing purposes there are possibility to reset.

Step to reproduce:
1. Launch ToggleApp.java
2. press "State: ungrouped" to set toggle button to selected. Two toggle buttons will be put in toggle group. According to documentation, it is impossible, for two toggle buttons to be selected in the same time, when they are in the same group.
3. Press "State: unbind" to bind two setting checkBoxes to two tested toggle buttons.
4. press the last check box ("This check box unidirectionally sets toggle button 2 selection property")
5.press the previous (3rd) check box ("This check box is bidirectionally binded to Toggle Button 1 selection property")

You can see, that both toggle buttons are selected, but that must be impossible.

Also, you can see, that if you unpress (unselect) "State: Unbinded" toggle button, then only one tested toggle button can be selected (that is the proof of the grouping).