in src/main/java/org/apache/sling/jobs/impl/JobSubsystem.java [131:138]
public synchronized void addConsumer(ServiceReference<JobConsumer> serviceRef) {
if (registrations.containsKey(serviceRef)) {
LOGGER.error("Registration for service reference is already present {}",serviceRef);
return;
}
JobConsumerHolder jobConsumerHolder = new JobConsumerHolder(serviceRef.getBundle().getBundleContext().getService(serviceRef), serviceRef);
registrations.put(serviceRef, jobConsumerHolder);
}