What is the usage/clarify of weaveAddLast in a camel route ?

Issue

• We have a route defined like the following,

from(EXAMPLE_ROUTE)
                .routeId(ROUTE_ID)
                .filter(header("TYPE").isNotEqualTo(FILTER))
                .choice()
                .when(header("TYPE").isEqualTo(TYPE1)).to("amq:" + QUEUE1)
                .when(header("TYPE").isEqualTo(TYPE2)).to("amq:" + QUEUE2)
                .when(header("TYPE").isEqualTo(TYPE3)).to("amq:" + QUEUE3)
                .otherwise().log(INFO, "Not interested with TYPE = ${header.TYPE}");

 And the following test failed on MOCK_END.expectedMessageCount(0);

 @Before
    public void routeSetup() throws Exception {
        String rrpQ = "mock:Q1";
        String rolloverQ = "mock:Q2";
        String outrightQ = "mock:Q3";
        String end = "mock:end";

        // Create AdviceWithRouteBuilder to Advice the Route
        AdviceWithRouteBuilder adviceWithRouteBuilder = new AdviceWithRouteBuilder() {
            @Override
            public void configure() throws Exception {
                weaveByToString("To[amq:" + QUEUE1 + "]").replace().to(rrpQ);
                weaveByToString("To[amq:" + QUEUE2 + "]").replace().to(outrightQ);
                weaveByToString("To[amq:" + QUEUE3 + "]").replace().to(rolloverQ);
                weaveAddLast().to(end);
            }
        };

 // Apply Advice to Route under Test
        context.getRouteDefinition(ROUTE_ID).adviceWith(context, adviceWithRouteBuilder);
        MOCK_Q1 = getMockEndpoint(rrpQ);
        MOCK_Q2 = getMockEndpoint(rolloverQ);
        MOCK_Q3 = getMockEndpoint(outrightQ);
        MOCK_END = getMockEndpoint(end);
    }

    @Test
    public void routingRRPEvent() throws Exception {
        // prepare
        context.start();

        // invoke
        template.sendBodyAndHeader(EXAMPLE_ROUTE, constant(null), "TYPE", TYPE1);

        // conditions to verify
        MOCK_Q2.expectedMessageCount(0);
        MOCK_Q3.expectedMessageCount(0);

        MOCK_Q1.expectedHeaderReceived("TYPE", TYPE1);
        MOCK_Q1.expectedMessageCount(1);

        MOCK_END.expectedMessageCount(0);  // failed

        // verify
        assertMockEndpointsSatisfied();
    }

• We are expecting the MOCK_END.expectedMessageCount to be 0 but what we actually get the result 1. When we exam the message with debug mode, we learned the message from MOCK_END is the same as MOCK_Q1.

• Can you please explains how weaveAddLast() works? We add more tests given different when condition and the MOCK_END is always give me the exactly the same message as the when condition we are getting.

• It looks like the weaveAddLast() add an node to the route end during runtime depends on wherever the given message is heading to, instead of just add the a node at the very end of the route definition?