code: public final <T> ServiceRegistration<?> registerService(Class<T> iface, T instance) {
  	Hashtable<String, String> properties = new Hashtable<String, String>();
  	return registerService(iface, instance, properties);
      }
docs: This method should be used to register services. Services registered with
  this method auto deregistered during bundle stop.
  
  @param iface
  is the interface of the service to be used for later retrieval.
  @param instance
  is an instance of the object to be registered as service for
  interface iface.
  @param <T>
  is the service interface.
  @return A {@link ServiceRegistration} is returned of the newly registered
  service.