public static  void checkDecoratorConditions(Class<?> decoratorClazz) 
{
       
        Set< Type > decoratorSet = new HashSet< Type >();
        ClassUtil.setInterfaceTypeHierarchy(decoratorSet, decoratorClazz);
        //No-Decorates found, check from super class
        if(!checkInternalDecoratorConditions(decoratorClazz, decoratorSet))
        {
           boolean found = checkInternalDecoratorConditionsRecursivley(decoratorClazz,decoratorSet);
           if(!found)
           {
               throw new WebBeansConfigurationException("Decorator delegate attribute for decorator class : " + decoratorClazz.getName() + " can not be found!");
           }
        }
}

Check decorator conditions.

 public static  void checkManagedBeanDecoratorConditions(ManagedBean<?> component) 
{
        Asserts.assertNotNull("component", "component parameter can not be null");
        Set< Annotation > annSet = component.getQualifiers();
        Annotation[] anns = new Annotation[annSet.size()];
        anns = annSet.toArray(anns);
        List< Decorator< ? > > decoratorList = BeanManagerImpl.getManager().resolveDecorators(component.getTypes(), anns);
        if (!decoratorList.isEmpty())
        {
            Class< ? > clazz = component.getReturnType();
            if (ClassUtil.isFinal(clazz.getModifiers()))
            {
                throw new WebBeansConfigurationException("Managed Bean : " + component.getReturnType().getName() + " can not be declared final, because it has one or more decorators");
            }
            Method[] methods = clazz.getDeclaredMethods();
            for (Method method : methods)
            {
                int modifiers = method.getModifiers();
                if (!ClassUtil.isStatic(modifiers) && !ClassUtil.isPrivate(modifiers) && ClassUtil.isFinal(modifiers))
                {
                    // Check decorator implements this
                    Iterator< Decorator< ? > > itDecorator = decoratorList.iterator();
                    while (itDecorator.hasNext())
                    {
                        WebBeansDecorator< ? > decorator = (WebBeansDecorator< ? >) itDecorator.next();
                        Class< ? > decClazz = decorator.getClazz();
                        try
                        {
                            if (decClazz.getMethod(method.getName(), method.getParameterTypes()) != null)
                            {
                                throw new WebBeansConfigurationException("Managed Bean : " + component.getReturnType().getName() + " can not define non-private, non-static, final method : " + method.getName() + ", because one of its decorators implements this method");
                            }
                        }
                        catch (SecurityException e)
                        {
                            logger.error("Security exception, can not access decorator class : " + decClazz.getName() + " method : " + method.getName(), e);
                            throw new WebBeansException(e);
                        }
                        catch (NoSuchMethodException e)
                        {
                            continue;
                        }
                    }
                }
            }
        }
}