code: private Object getServiceHandler(IScope scope, String serviceName) {
          // get application scope handler first
          Object service = scope.getHandler();
          if (serviceName == null || serviceName.equals("")) {
              // no service requested, return application scope handler
              log.trace("No service requested, return application scope handler: {}", service);
              return service;
          }
          // search service resolver that knows about service name
          for (IServiceResolver resolver : serviceResolvers) {
              service = resolver.resolveService(scope, serviceName);
              if (service != null) {
                  return service;
              }
          }
          // requested service does not exist
          return null;
      }
docs: Lookup a handler for the passed service name in the given scope.
  
  @param scope
  Scope
  @param serviceName
  Service name
  @return Service handler