code: /** 
   * Test method for {@link org.apache.dubbo.registry.support.AbstractRegistry#unregister(URL)}.
   * @throws Exception
   */
  @Test public void testUnregister() throws Exception {
    URL url=new URL("dubbo","192.168.0.1",2200);
    abstractRegistry.getRegistered().add(url);
    abstractRegistry.unregister(url);
    Assert.assertThat(false,Matchers.equalTo(abstractRegistry.getRegistered().contains(url)));
    abstractRegistry.getRegistered().clear();
    List<URL> urlList=getList();
    for (  URL urlSub : urlList) {
      abstractRegistry.getRegistered().add(urlSub);
    }
    for (  URL urlSub : urlList) {
      abstractRegistry.unregister(urlSub);
    }
    Assert.assertThat(0,Matchers.equalTo(abstractRegistry.getRegistered().size()));
  }
  