def test_non_imgur(self):
     with self.assertRaises(DoesNotKnowHowToGetUrl):
         get_thumbnails('http://google.com/xyzxyz.jpg')
 def test_png(self):
     self.assertItemsEqual(get_thumbnails('http://i.imgur.com/xyzxyz.png'),
                           ['http://i.imgur.com/xyzxyzt.png'])