static void Main(string[] args)
        {
            var builder = new ConfigurationBuilder();

            builder.SetBasePath(Directory.GetCurrentDirectory())
            .AddXmlFile("App.config", optional: true, reloadOnChange: true)
            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);

            builder.AddEnvironmentVariables();
            Configuration = builder.Build();

            var simple = new SimpleInjector.Container();

            simple.AddOptions(Configuration);

            foreach (var v in Configuration.AsEnumerable())
            {
                Console.WriteLine($"{v.Key} : {v.Value}");
            }

            var dbOptions = simple.GetInstance <IOptions <DatabaseSettings> >();

            Console.WriteLine($"DB Name : {dbOptions.Value.Name}");
            Console.ReadKey();
        }