@NonNull
	public ValueChangedCallback then(@NonNull final ClosedCallback callback) {
		this.closedCallback = callback;
		return this;
	}
Sets a callback that will be executed when the device services were invalidated (i.e. on
disconnection) or the callback has been unregistered and it can release resources.

@param callback the callback.
@return The request.
ble/src/main/java/no/nordicsemi/android/ble/ValueChangedCallback.java