Adds an action to the action group.
If the action group already contains an action with the same name as action then the old action is dropped from the group.
The action group takes its own reference on action.
a #GAction
Deprecated: Use gio.action_map.ActionMap.addAction
Adds an action to the action group.
If the action group already contains an action with the same name as action then the old action is dropped from the group.
The action group takes its own reference on action.