Code in ReadMe Doesn't Compile about authorization HOT 9 CLOSED

namespace BasicSample
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Security.Claims;
    using System.Threading.Tasks;
    using Microsoft.Extensions.DependencyInjection;
    using GraphQL;
    using GraphQL.Types;
    using GraphQL.Validation;
    using GraphQL.SystemTextJson;

    using GraphQL.Authorization;

    class Program
    {
        static async Task Main(string[] args)
        {
            var services = new ServiceCollection();
            services.AddSingleton<IAuthorizationEvaluator, AuthorizationEvaluator>();
            services.AddTransient<IValidationRule, AuthorizationValidationRule>();
            services.AddTransient(s =>
            {
                var authSettings = new AuthorizationSettings();
                authSettings.AddPolicy("AdminPolicy", p => p.RequireClaim("role", "Admin"));
                return authSettings;
            });

            var serviceProvider = services.BuildServiceProvider();

            var definitions = @"
                type User {
                    id: ID
                    name: String
                }

                type Query {
                    viewer: User
                    users: [User]
                }
            ";
            var schema = Schema.For(
                definitions,
                _ =>
                {
                    _.Types.Include<Query>();
                });

            // remove claims to see the failure
            var authorizedUser = new ClaimsPrincipal(new ClaimsIdentity(new[] { new Claim("role", "Admin") }));

            var json = await schema.ExecuteAsync(_ =>
            {
                _.Query = "{ viewer { id name } }";
                _.ValidationRules = serviceProvider
                    .GetServices<IValidationRule>()
                    .Concat(DocumentValidator.CoreRules);
                _.RequestServices = serviceProvider;
                _.UserContext = new GraphQLUserContext { User = authorizedUser };
            });

            Console.WriteLine(json);
        }
    }

    public class GraphQLUserContext : Dictionary<string, object>, IProvideClaimsPrincipal
    {
        public ClaimsPrincipal User { get; set; }
    }

    public class Query
    {
        [GraphQLAuthorize(Policy = "AdminPolicy")]
        public User Viewer()
        {
            return new User { Id = Guid.NewGuid().ToString(), Name = "Quinn" };
        }

        public List<User> Users()
        {
            return new List<User> { new User { Id = Guid.NewGuid().ToString(), Name = "Quinn" } };
        }
    }

    public class User
    {
        public string Id { get; set; }
        public string Name { get; set; }
    }
}