The App Check instance.
The listener to register.
Unsubscribe
Registers a listener to changes in the token state. There can be more than one listener registered at the same time for one or more App Check instances. The listeners call back on the UI thread whenever the current token associated with this App Check instance changes.
The App Check instance.
The callback function for token changes.
OptionalonError: (error: Error) => voidOptional error callback.
OptionalonCompletion: () => voidOptional completion callback.
Unsubscribe
Registers a listener to changes in the token state. There can be more than one listener registered at the same time for one or more App Check instances. The listeners call back on the UI thread whenever the current token associated with this App Check instance changes.