code: @Reference(cardinality=ReferenceCardinality.OPTIONAL, policyOption=ReferencePolicyOption.GREEDY)
      protected void setExpressionFactoryService(ServiceReference<ELFactoryWrapperForCDI> expressionFactoryService) {
          this.expressionFactoryService.setReference(expressionFactoryService);
      }
docs: Inject an <code>WrapperExpressionFactory</code> service instance.
  
  @param expressionFactoryService
  an expressionFactory service to wrap the default ExpressionFactory