private ChangingEventArgs RaiseOnChangingSync(string key, object data)
        {
            var e = new ChangingEventArgs
            {
                Key      = key,
                OldValue = ((ISyncLocalStorageService)this).GetItem <object>(key),
                NewValue = data
            };

            Changing?.Invoke(this, e);
            return(e);
        }
        private async Task <ChangingEventArgs> RaiseOnChangingAsync(string key, object data)
        {
            var e = new ChangingEventArgs
            {
                Key      = key,
                OldValue = await GetItem <object>(key),
                NewValue = data
            };

            Changing?.Invoke(this, e);

            return(e);
        }