How to send Context Information from service bean to message composer in FSW 6?

Issue

For a new Switchyard service exposed by http binding, we need to set some context information within a service bean, and retrieve that information in the message composer before sending the response.

We are able to set the context information for the incoming message in a custom Http message composer:

public class BaseHttpComposer extends BaseMessageComposer<HttpBindingData> {

    public Message compose(HttpBindingData httpBindingData, Exchange exchange)
            throws Exception {
        HttpRequestBindingData request = (HttpRequestBindingData) httpBindingData;
        String body = request.getBodyAsString();
        Message m = exchange.createMessage();
        System.out.println("BaseHttpComposer.compose()-> set myFlag = 1");
        m.getContext().setProperty("myFlag", "1");      
        m.setContent(body);
        return m;
    }

This context property is available in the bean implementation:

    public String process(String content) throws Exception {
        Message message  = exchange.getMessage();
        String myflag = message.getContext().getPropertyValue("myFlag").toString()
                return "InnerBean.process() -> myFlag = " + myflag;
        }

However, in the decompose method of the custom http message composer, the property is missing:

    public HttpBindingData decompose(Exchange exchange, HttpBindingData httpBindingData)
            throws Exception {
        String body = (String) exchange.getMessage().getContent().toString();
        String myFlag = (String) exchange.getMessage().getContext().getPropertyValue("myFlag");  // <-- context property is NULL here!?
        System.out.println("BaseHttpComposer.decompose() -> myFlag = " + myFlag);

        HttpResponseBindingData response = (HttpResponseBindingData) httpBindingData;
        /* response manipulation */
        return response;
    }