@Test
  public void setLayerCalculator() {
    LayerCalculatorImpl calc = new LayerCalculatorImpl();
    network.setLayerCalculator(calc);

    assertEquals(calc, network.getLayerCalculator());
  }
 @Test
 public void uninitializedNetworkDoesntHaveALayerCalculator() {
   assertNull(network.getLayerCalculator());
 }