public void testtop10Tracks() {
   Spotify model = new Spotify();
   List<Track> results = model.top10Tracks("04gDigrS5kc9YWfZHwBETP", "US");
   assertNotNull(results);
 }
 public void testSearchForArtist() throws Exception {
   Spotify model = new Spotify();
   List<Artist> results = model.searchForArtist("Maroon 5");
   assertNotNull(results);
 }