Arquivo de startup web api 2

Startup.cs

namespace Interface.Api
{
    public class Startup
    {
        private static readonly string _urlBase = ConfigurationManager.AppSettings["UrlBase"];
        private static readonly string _allowInsecureHttp = ConfigurationManager.AppSettings["AllowInsecureHttp"];

        public void Configuration(IAppBuilder app)
        {
            HttpConfiguration config = new HttpConfiguration
            {
                DependencyResolver = new UnityDependencyResolver(UnityConfig.RegisterComponents())
            };

            ConfigureWebApi(config);
            ConfigureContracts(config);
            ConfigureOAuth(app);
            ConfigureCors(app);
            app.UseWebApi(config);
        }

        private static void ConfigureWebApi(HttpConfiguration config)
        {
            config.MapHttpAttributeRoutes();
            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }

        private static void ConfigureOAuth(IAppBuilder app)
        {
            var optionsConfigurationsToken = new OAuthAuthorizationServerOptions
            {
                AllowInsecureHttp = Convert.ToBoolean(_allowInsecureHttp),
                TokenEndpointPath = new PathString("/api/v1/token"),
                AccessTokenExpireTimeSpan = TimeSpan.FromHours(8),

                // Para gerar Bearer token
                Provider = new ProviderTokensAccess(),

                // Para gerar token JWT
                // Provider = new CustomOAuthProviderJwt(),
                // AccessTokenFormat = new CustomJwtFormat(_urlBase)
            };

            app.UseOAuthAuthorizationServer(optionsConfigurationsToken);
            app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
        }

        private static void ConfigureContracts(HttpConfiguration config)
        {
            //config.Formatters.OfType<JsonMediaTypeFormatter>().First();
            //config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            config.Formatters.JsonFormatter.UseDataContractJsonSerializer = false;
            config.Formatters.JsonFormatter.SerializerSettings.Re‌​ferenceLoopHandling = ReferenceLoopHandling.Ignore;
        }

        private static void ConfigureCors(IAppBuilder app)
        {
            var policy = new CorsPolicy
            {
                AllowAnyHeader = true,
                AllowAnyMethod = true,
                AllowAnyOrigin = true
            };

            //politica.Origins.Add("http://localhost:40874");
            //politica.Origins.Add("http://localhost:40880");
            //politica.Methods.Add("GET");
            //politica.Methods.Add("POST");

            var corsOptions = new CorsOptions
            {
                PolicyProvider = new CorsPolicyProvider
                {
                    PolicyResolver = context => Task.FromResult(policy)
                }
            };

            app.UseCors(corsOptions);
        }
    }
}