public string Add(K key, T item)
        {
            var newEle = new PersistantDictionaryElement <K, T>(key, item);

            _collection.InsertOneAsync(newEle).Wait();

            _localCache.Add(newEle);

            return(newEle.Id);
        }
        public PersistantDictionaryUpdateContext(PersistantDictionary <K, T> dictionary, string id, bool async = false)
        {
            _dictionary = dictionary;
            _id         = id;
            _element    = dictionary.Get(id);

            KeyObject  = _element.KeyObject;
            DataObject = _element.DataObject;

            _async = async;
        }