public  ServiceFactory()
        {
            var services = new ServiceCollection();
            services.AddDbContext<ApplicationDbContext>
            (
                options => options.UseInMemoryDatabase(Guid.NewGuid().ToString())

            );


            IdentityBuilder builder = services.AddIdentityCore<User>(options =>
            {
                options.Password.RequireDigit = false;
                options.Password.RequireUppercase = false;
                options.Password.RequiredLength = 8;
                options.Password.RequireDigit = false;
                options.Password.RequireLowercase = false;
                options.Password.RequireNonAlphanumeric = false;
            });
            builder = new IdentityBuilder(builder.UserType, typeof(Role), builder.Services);

            builder.AddEntityFrameworkStores<ApplicationDbContext>();
            builder.AddRoleValidator<RoleValidator<Role>>();
            builder.AddRoleManager<RoleManager<Role>>();
            builder.AddSignInManager<SignInManager<User>>();
            // Taken from https://github.com/aspnet/MusicStore/blob/dev/test/MusicStore.Test/ManageControllerTest.cs (and modified)
            // IHttpContextAccessor is required for SignInManager, and UserManager
            var context = new DefaultHttpContext();
            context.Features.Set<IHttpAuthenticationFeature>(new HttpAuthenticationFeature());
            services.AddSingleton<IHttpContextAccessor>(h => new HttpContextAccessor { HttpContext = context });
            var serviceProvider = services.BuildServiceProvider();
            this.Context = serviceProvider.GetRequiredService<ApplicationDbContext>();
            this.UserManager = serviceProvider.GetRequiredService<UserManager<User>>();

        }