Missing an hint that the error message "Unable to generate WSDL for this service" is irrelevant

I tried the example printed on the online-documentation "Apache Axis2 User's Guide -Building Services"

http://ws.apache.org/axis2/1_1_1/userguide-buildingservices.html#buildservices

Before I invoked

java SampleClient

I browsed the web page

http://localhost:8080/axis2/services/listServices

and clicked the link

http://localhost:8080/axis2/services/UserGuideSampleService?wsdl

named "UserGuideSampleService".

Unfortunately a web page with the error message "Unable to generate WSDL for this service" is returned. Therefore I thougt something is going wrong with the sample and tried to figure out a solution for this issue by browsing the web. But two hours later I identified that the reported error message is irrelevant for the sample There is no need to pay attention to the error message for a successful invocation of the service.

In my humble opinion a hint regarding the irrelevance of the error message should be stated on the web page

http://ws.apache.org/axis2/1_1_1/userguide-buildingservices.html#buildservices