Adds an object of the type RibbonGroup to the end of the collection.
[C#] public int Add(Windows.Forms.Ribbon.RibbonGroup ribbonGroup);
[Visual Basic] Public Function Add(ribbonGroup item As Windows.Forms.Ribbon.RibbonGroup) As Integer
The RibbonGroup to be added to the end of the collection.
The collection's index at which the value has been added.