in src/main/java/org/apache/sling/commons/scheduler/impl/QuartzScheduler.java [296:301]
private void checkJob(final Object job)
throws IllegalArgumentException {
if (!(job instanceof Runnable) && !(job instanceof Job)) {
throw new IllegalArgumentException("Job object is neither an instance of " + Runnable.class.getName() + " nor " + Job.class.getName());
}
}