SizeGroup.setMode

Sets the #GtkSizeGroupMode of the size group. The mode of the size group determines whether the widgets in the size group should all have the same horizontal requisition ([gtk.types.SizeGroupMode.Horizontal]) all have the same vertical requisition ([gtk.types.SizeGroupMode.Vertical]), or should all have the same requisition in both directions ([gtk.types.SizeGroupMode.Both]).