code: protected void unsetItemInterface(ServiceReference<ItemInterface> ref) {
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
              SibTr.entry(tc, "unsetItemInterface", ref);
          itemInterfaceRef.setReference(ref);
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
              SibTr.exit(tc, "unsetItemInterface");
  
      }
docs: Declarative Services method for unsetting the ItemInterface service
  reference.
  
  @param ref
  reference to the service