in src/main/java/org/apache/sling/junit/performance/runner/PerformanceRunner.java [109:117]
private void validateListenMethodsReturnType(List<Throwable> errors) {
for (FrameworkMethod method : getTestClass().getAnnotatedMethods(Listen.class)) {
if (Listener.class.isAssignableFrom(method.getReturnType())) {
continue;
}
errors.add(new Error("Method " + method.getName() + "() should return an object of type Listener"));
}
}