using System;

using System.Threading.Tasks;

using System.Net;

using System.Net.Http;

using DalSoft.RestClient;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

public class Program

{

    public async static Task Main()

    {

        var client = new RestClient("https://jsonplaceholder.typicode.com", new Config()

                                    .SetJsonSerializerSettings(new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() }));

        await client

            .Resource<UserResource>(api => api.GetUser(1)).Get()

            .Verify<User>(user => user.Username == "Fail")

            .Verify<HttpResponseMessage>(response => response.StatusCode == HttpStatusCode.BadRequest);   

    }

    public class UserResource

    {

        public string GetUsers() => "users";

​

        public string GetUser(int userId) => $"{GetUsers()}/{userId}";

        public string GetUserPosts(int userId) => $"{GetUser(userId)}/posts";

    }

    public class User

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public string Username { get; set; }

        public string Email { get; set; }

        public string Phone { get; set; }

        public string Website { get; set; }

    }

}