Body type problem on CXF component with CXF_MESSAGE dataFormat`

Hi All:

I have a question about the expect body type of CXF compoent when using
CXF_MESSAGE dataFormat. My CXF version is 2.7.5 and Camel version is 2.10.4.

for example, I have a route:timer -> setBody (constant string content) ->
CXF
It works fine, if dataFormat of this cxf component is RAW, POJO or PAYLOAD,
But, if dataFormat is CXF_MESSAGE, then the output request body is always
empty, In order to make it work, I have to append a convertBodyTo
component: timer -> setBody (constant string content) -> convertBodyTo
(javax.xml.transform.Source.class) -> CXF

I checked the code, the Source type is required in method handleMessage of
org.apache.cxf.jaxws.interceptors.MessageModeOutInterceptor.MessageModeOutInterceptorInternal

As my understand, if the Source type is required, then this should be done
inside Camel. else user may don't understand what's wrong.