backward compatibility write handler

gistfile1.java

  static class JASPIAuthenticationModulesAttributeWriter implements OperationStepHandler {
        @Override
        public void execute(OperationContext context, ModelNode operation) throws OperationFailedException {
            OperationStepHandler addHandler = context.getResourceRegistration().getSubModel(PathAddress.EMPTY_ADDRESS.append(AUTH_MODULE)).getOperationHandler(PathAddress.EMPTY_ADDRESS, "add");
            for (ModelNode module : operation.get(VALUE).asList()) {
                ModelNode addModuleOp = module.clone();
                String code = addModuleOp.get(CODE).asString();
                PathElement relativePath = PathElement.pathElement(AUTH_MODULE, code);
                PathAddress address = PathAddress.pathAddress(operation.get(OP_ADDR)).append(relativePath);
                boolean exists = context.readResource(PathAddress.EMPTY_ADDRESS).hasChild(relativePath);
                if (exists) {
                    ModelNode removeModuleOp = Util.createRemoveOperation(address);
                    context.addStep(removeModuleOp, new SecurityDomainReloadRemoveHandler(), OperationContext.Stage.IMMEDIATE);
                }
                addModuleOp.get(OP_ADDR).set(address.toModelNode());
                addModuleOp.get(OP).set(ADD);
                context.addStep(addModuleOp, addHandler, OperationContext.Stage.IMMEDIATE);
                context.stepCompleted();
            }
        }
    }