### Question:
Layer implements Iterable<Neuron>, Serializable { public final void removeNeuronAt(int index) { Neuron neuron = neurons.get(index); neuron.setParentLayer(null); neuron.removeAllConnections(); neurons.remove(index); if (parentNetwork != null) parentNetwork.fireNetworkEvent(new NeuralNetworkEvent(this, NeuralNetworkEvent.Type.NEURON_REMOVED)); } Layer();  Layer(int neuronsCount);  Layer(int neuronsCount, NeuronProperties neuronProperties); final void setParentNetwork(NeuralNetwork parent); final NeuralNetwork getParentNetwork(); final List<Neuron> getNeurons(); final void addNeuron(Neuron neuron); final void addNeuron(int index, Neuron neuron); final void setNeuron(int index, Neuron neuron); final void removeNeuron(Neuron neuron); final void removeNeuronAt(int index); final void removeAllNeurons(); Neuron getNeuronAt(int index); int indexOf(Neuron neuron); int getNeuronsCount(); void calculate(); void reset(); void initializeWeights(double value); String getLabel(); void setLabel(String label); boolean isEmpty(); @Override Iterator<Neuron> iterator();  }### Answer:
@Test public void testRemoveNeuronAt() { instance.removeNeuronAt(0); assertEquals(1, instance.getNeuronsCount()); }