Objective
The Add Sibling Pane menu is used to add a Pane under the same GroupPane as the selected Pane. Basically it has the same functionality as AddPane.The only difference is when clicked a "sibling" Pane is created not child Pane. This menu is only visible when a Pane is selected.
SnapShots
- Before the "Add Sibling Pane is clicked.

- After the "Add Sibling Pane" is clicked, notice the new Pane added.
