@Test
 public void testFeedForwardActivationsAndDerivatives() {
   MultiLayerNetwork network = new MultiLayerNetwork(getConf());
   network.init();
   DataSet data = new IrisDataSetIterator(1, 150).next();
   network.fit(data);
   Pair result = network.feedForwardActivationsAndDerivatives();
   List<INDArray> first = (List) result.getFirst();
   List<INDArray> second = (List) result.getSecond();
   assertEquals(first.size(), second.size());
 }