public void GetNextSongPathTest()
        {
            PlayListModel playListModel = new PlayListModel
            {
                SongPath = path
            };

            PlayListViewModel.ListBoxItems.Add(playListModel);

            Assert.AreEqual(path, playListViewModel.GetNextSongPath(-1));
            Assert.AreEqual(path, playListViewModel.GetNextSongPath(5));
            PlayListViewModel.ListBoxItems.Clear();

            Assert.IsNull(playListViewModel.GetNextSongPath(0));
        }