code: @Reference(service = WSContextService.class,
                 policy = ReferencePolicy.DYNAMIC,
                 policyOption = ReferencePolicyOption.GREEDY,
                 target = "(id=unbound)")
      protected void setContextService(ServiceReference<WSContextService> ref) {
          contextSvcRef.setReference(ref);
      }
docs: Declarative Services method for setting the context service reference
  
  @param ref reference to the service