/**
  * Tests vRouterMacs getter.
  *
  * @throws Exception
  */
 @Test
 public void testVRouterMacs() throws Exception {
   Set<MacAddress> vRouterMacs = config.vRouterMacs();
   assertNotNull("vRouterMacs should not be null", vRouterMacs);
   assertThat(vRouterMacs.size(), is(2));
   assertTrue(vRouterMacs.contains(ROUTER_MAC_1));
   assertTrue(vRouterMacs.contains(ROUTER_MAC_2));
 }
  /**
   * Tests vRouterMacs setter.
   *
   * @throws Exception
   */
  @Test
  public void testSetVRouterMacs() throws Exception {
    ImmutableSet.Builder<MacAddress> builder = ImmutableSet.builder();
    builder.add(ROUTER_MAC_3);
    config.setVRouterMacs(builder.build());

    Set<MacAddress> vRouterMacs = config.vRouterMacs();
    assertThat(vRouterMacs.size(), is(1));
    assertTrue(vRouterMacs.contains(ROUTER_MAC_3));
  }