private void TweetListrowRemoveThis(object sender, EventArgs e)
        {
            var rowToRemove = sender as TweetListRowViewModel;

            if (rowToRemove == null)
            {
                return;
            }

            rowToRemove.StopStreaming();
            TweetListRows.Remove(rowToRemove);
            RaisRemoveMapPoints(rowToRemove);
        }
        private void OnAddTweetListRow(object obj)
        {
            if (obj == null)
            {
                return;
            }

            string hashtag = obj.ToString();

            if (string.IsNullOrEmpty(hashtag) ||
                TweetListRows.Any(item => item.Hashtag.Equals(hashtag, StringComparison.OrdinalIgnoreCase)))
            {
                return;
            }

            var listRow = new TweetListRowViewModel(hashtag);

            listRow.MapPointAdded += TweetListRowMapPointAdded;
            listRow.RemoveThisRow += TweetListrowRemoveThis;

            TweetListRows.Add(listRow);
            listRow.StartStreaming();
        }