buttonLabel 
  The label to show on the button.
If set to "" or NULL, the button won't be shown.
The button can be used with a GAction, or with the signal@Banner::button-clicked signal.
Since
1.3
The label to show on the button.
If set to "" or NULL, the button won't be shown.
The button can be used with a GAction, or with the signal@Banner::button-clicked signal.
1.3