code: /** 
   * Test method for {@link org.apache.dubbo.registry.support.AbstractRegistry#unsubscribe(URL,NotifyListener)}.
   * @throws Exception
   */
  @Test public void testUnsubscribe() throws Exception {
    try {
      abstractRegistry.unsubscribe(testUrl,null);
      Assert.fail();
    }
   catch (  Exception e) {
      Assert.assertTrue(e instanceof IllegalArgumentException);
    }
    try {
      abstractRegistry.unsubscribe(null,null);
      Assert.fail();
    }
   catch (  Exception e) {
      Assert.assertTrue(e instanceof IllegalArgumentException);
    }
    Assert.assertNull(abstractRegistry.getSubscribed().get(testUrl));
    abstractRegistry.subscribe(testUrl,listener);
    abstractRegistry.unsubscribe(testUrl,listener);
    Assert.assertNotNull(abstractRegistry.getSubscribed().get(testUrl));
    Assert.assertFalse(abstractRegistry.getSubscribed().get(testUrl).contains(listener));
  }
  