问Xamarin.ios -使用NBuilder构建模拟抛出TypeCreationException

EN

public class Actor
    {
        public Actor() {
        }



        [JsonProperty("authorities")]
        public List<Authority> Authorities { get; set; }
        [JsonProperty("imageDerivatives")]
        public ImageDerivatives ImageDerivatives { get; set; }
        [JsonProperty("profileFileId")]
        public PictureFile ProfilePicture { get; set; }
        [JsonProperty("role")]
        public Role Role { get; set; }
        [JsonProperty("roleId")]
        public int RoleId { get; set; }
        [JsonProperty("status")]
        public bool Status { get; set; }
        [JsonProperty("updatedAt")]
        public DateTime UpdatedAt { get; set; }
        [JsonProperty("username")]
        public string Username { get; set; }
        [JsonProperty("createdAt")]
        public DateTime CreatedAt { get; set; }
        [JsonProperty("departmentId")]
        public int DepartmentId { get; set; }
        [JsonProperty("email")]
        public string Email { get; set; }
        [JsonProperty("firstName")]
        public string FirstName { get; set; }
        [JsonProperty("id")]
        public int Id { get; set; }
        [JsonProperty("isAppAdmin")]
        public bool IsAppAdmin { get; set; }
        [JsonProperty("lastName")]
        public string LastName { get; set; }
        [JsonProperty("password")]
        public string Password { get; set; }
    }

private Actor GetRandomActor()
        {
            return Builder<Actor>.CreateNew()
                .With(a => a.FirstName = GetRandomFirstName())
                .With(a => a.LastName = GetRandomLastName())
                .With(a => a.ProfilePicture = GetRandomPictureFile())
                .With(a => a.Email = GetRandomEmail())
                .With(a => a.Username = GetRandomUserName())
                .Build();
        }