code: @Test public void getOrAddChannelTest01(){
    channel=new MockChannel(){
      @Override public URL getUrl(){
        return url;
      }
      @Override public boolean isConnected(){
        return true;
      }
    }
  ;
    Assert.assertNull(channel.getAttribute(CHANNEL_KEY));
    HeaderExchangeChannel ret=HeaderExchangeChannel.getOrAddChannel(channel);
    Assert.assertNotNull(ret);
    Assert.assertNotNull(channel.getAttribute(CHANNEL_KEY));
    Assert.assertEquals(channel.getAttribute(CHANNEL_KEY).getClass(),HeaderExchangeChannel.class);
  }
  