How to generate JUnit XML reports in Codename One?

From the documentation of Codename One, we see that there is a class for generating JUnit XML reports - com.codename1.testing.JUnitXMLReporting. However, I do not know how to actually use it to create reports. Where in build.xml should I tell the class that will generate the report? Or if this is not the way this class is used, then how?