private Object callMethod(Object receiver, String name, Object... args) {
   try {
     java.lang.reflect.Method m =
         receiver.getClass().getMethod(name, testSupport.collectArgTypes(args));
     return m.invoke(receiver, args);
   } catch (Throwable e) {
     e.printStackTrace();
   }
   return null;
 }
 private Object instantiate(String className) {
   return testSupport.instantiate(className);
 }