The initial UIRawMessage value for this observable.
Optionaloptions: ObservableOptionsOptional configuration for the observable, such as whether the value can be written by the client.
The new UIRawMessage value to set.
A function that receives the new UIRawMessage value each time the observable changes.
The callback handle previously returned by subscribe.
Rc
An observable that holds a UIRawMessage value. Listeners are notified whenever the value changes.