private async Task EnsureCharacteristicManagerCreated()
 {
     if (_characteristicManager == null)
     {
         _characteristicManager = await this.CreateCharacteristicManager();
     }
 }
 private async Task EnsureCharacteristicManagerCreated()
 {
     if (_characteristicManager == null)
     {
         _characteristicManager = await this.CreateCharacteristicManager();
     }
 }
        //private readonly IToastNotification _toast;

        public CharacteristicController(ICharacteristicManager characteristicManager)//, IToastNotification toast)
        {
            _characteristicManager = characteristicManager;
            //_toast = toast;
        }