### Question:
NeuralNetwork implements Serializable { public Double[] getWeights() { List<Double> weights = new ArrayList(); for (Layer layer : layers) { for (Neuron neuron : layer.getNeurons()) { for (Connection conn : neuron.getInputConnections()) { weights.add(conn.getWeight().getValue()); } } } return weights.toArray(new Double[weights.size()]); } NeuralNetwork(); void addLayer(Layer layer); void addLayer(int index, Layer layer); void removeLayer(Layer layer); void removeLayerAt(int index); List<Layer> getLayers(); Layer getLayerAt(int index); int indexOf(Layer layer); int getLayersCount(); void setInput(double... inputVector); double[] getOutput(); void calculate(); void reset(); void learn(DataSet trainingSet); void stopLearning(); void pauseLearning(); void resumeLearning(); void randomizeWeights(); void randomizeWeights(double minWeight, double maxWeight); void randomizeWeights(Random random); void randomizeWeights(WeightsRandomizer randomizer); NeuralNetworkType getNetworkType(); void setNetworkType(NeuralNetworkType type); List<Neuron> getInputNeurons(); int getInputsCount(); void setInputNeurons(List<Neuron> inputNeurons); List<Neuron> getOutputNeurons(); int getOutputsCount(); void setOutputNeurons(List<Neuron> outputNeurons); void setOutputLabels(String[] labels); String[] getOutputLabels(); L getLearningRule(); void setLearningRule(L learningRule); Double[] getWeights(); void setWeights(double[] weights); boolean isEmpty(); void createConnection(Neuron fromNeuron, Neuron toNeuron, double weightVal); @Override String toString(); void save(String filePath); static NeuralNetwork load(String filePath); static NeuralNetwork load(InputStream inputStream); static NeuralNetwork createFromFile(File file); static NeuralNetwork createFromFile(String filePath); void addPlugin(PluginBase plugin); T getPlugin(Class<T>  pluginClass); void removePlugin(Class pluginClass); String getLabel(); void setLabel(String label); synchronized void addListener(NeuralNetworkEventListener listener); synchronized void removeListener(NeuralNetworkEventListener listener); synchronized void fireNetworkEvent(NeuralNetworkEvent evt);  }### Answer:
@Test public void testGetWeights() { assertTrue(instance.getWeights().length == 0); Layer l1 = new Layer(); l1.addNeuron(new Neuron()); l1.addNeuron(new Neuron()); Layer l2 = new Layer(); l2.addNeuron(new Neuron()); instance.addLayer(l1); instance.addLayer(l2); instance.createConnection(l1.getNeuronAt(0), l2.getNeuronAt(0), 5); instance.createConnection(l1.getNeuronAt(1), l2.getNeuronAt(0), 3); assertTrue(instance.getWeights().length == 2); assertTrue(instance.getWeights()[0] == 5); assertTrue(instance.getWeights()[1] == 3); }