public static async Task<IApplicationBuilder> UseOcelot(this IApplicationBuilder builder, OcelotPipelineConfiguration pipelineConfiguration){var configuration = await CreateConfiguration(builder);             //  ***}private static async Task<IInternalConfiguration> CreateConfiguration(IApplicationBuilder builder){// make configuration from file system?// earlier user needed to add ocelot files in startup configuration stuff, asp.net will map it to thisvar fileConfig = builder.ApplicationServices.GetService<IOptionsMonitor<FileConfiguration>>();// now create the config// ***fileConfig.OnChange(async (config) =>{var newInternalConfig = await internalConfigCreator.Create(config);internalConfigRepo.AddOrReplace(newInternalConfig.Data);});}

  public interface IOptionsMonitor<out TOptions>{TOptions CurrentValue { get; }TOptions Get(string name);IDisposable OnChange(Action<TOptions, string> listener);}

  public static IServiceCollection AddOptions(this IServiceCollection services){           //  ***services.TryAdd(ServiceDescriptor.Singleton(typeof(IOptionsMonitor<>), typeof(OptionsMonitor<>)));return services;}

      public static void Main(string[] args){BuildWebHost(args).Run();}public static IWebHost BuildWebHost(string[] args) =>WebHost.CreateDefaultBuilder(args).ConfigureAppConfiguration((context, builder) => {builder.SetBasePath(context.HostingEnvironment.ContentRootPath).AddJsonFile("Ocelot.json");}).UseUrls("http://localhost:6000").UseStartup<Startup>().Build();

public static IConfigurationBuilder AddJsonFile(this IConfigurationBuilder builder, IFileProvider provider, string path, bool optional, bool reloadOnChange)