// <summary>
        /// Register dependencies
        /// </summary>
        /// <param name="services">Collection of service descriptors</param>
        /// <param name="typeFinder">Type finder</param>
        /// <param name="nopConfig">Nop configuration parameters</param>
        protected virtual IServiceProvider RegisterDependencies(IServiceCollection services, ITypeFinder typeFinder, ArtConfig config)
        {
            var containerBuilder = new ContainerBuilder();

            //register instance object engine
            containerBuilder.RegisterInstance(this).As <IEngine>().SingleInstance();

            //register instance object type finder
            containerBuilder.RegisterInstance(typeFinder).As <ITypeFinder>().SingleInstance();

            // Once you've registered everything in the ServiceCollection, call
            // Populate to bring those registrations into Autofac. This is
            // just like a foreach over the list of things in the collection
            // to add them to Autofac.
            containerBuilder.Populate(services);

            //find dependency registrars provided by other assemblies
            var dependencyRegistrars = typeFinder.FindClassesOfType <IDependencyRegistrar>();

            //create and sort instances of dependency registrars
            var instances = dependencyRegistrars
                            .Select(dependencyRegistrar => (IDependencyRegistrar)Activator.CreateInstance(dependencyRegistrar))
                            .OrderBy(dependencyRegistrar => dependencyRegistrar.Order);

            //register all provided dependencies
            foreach (var dependencyRegistrar in instances)
            {
                dependencyRegistrar.Register(containerBuilder, typeFinder, config);
            }

            //create service provider
            _serviceProvider = new AutofacServiceProvider(containerBuilder.Build());

            return(_serviceProvider);
        }
        public IServiceProvider ConfigureServices(IServiceCollection services, IConfiguration configuration, ArtConfig config)
        {
            //find startup configurations provided by other assemblies
            var typeFinder            = new WebAppTypeFinder();
            var startupConfigurations = typeFinder.FindClassesOfType <IArticleStartup>();

            //create and sort instances of startup configurations
            var instances = startupConfigurations
                            .Select(startup => (IArticleStartup)Activator.CreateInstance(startup))
                            .OrderBy(startup => startup.Order);

            //configure services
            foreach (var instance in instances)
            {
                instance.ConfigureServices(services, configuration);
            }


            //register dependencies
            RegisterDependencies(services, typeFinder, config);

            return(_serviceProvider);
        }