C# Invitation

 public class Invitation
    {
   public Invitation()
        {
            Errors = new Error();
            Organization = new Organization();
            Groups = new List<Group>();
            Group = new Group();
            MachineUser = new MachineUser();
        }
        public Error Errors { get; set; }
        public string Email { get; set; }
        public Organization Organization { get; set; }
        public List<Group> Groups { get; set; }
        public Group Group { get; set; }
        public MachineUser MachineUser { get; set; }
        public int OrganizationId { get; set; }
        public int GroupId { get; set; }
        public int MachineUserId { get; set; }
    }

    public class Error
    {
        public string Code { get; set; }
    }

    public class Organization
    {
        public string Name { get; set; }
        public int Id { get; set; }
        public string Token { get; set; }
        public string UniqueCode { get; set; }
    }

    public class Group
    {
        public int Id { get; set; }
        public string Name { get; set; }

        public override string ToString()
        {
            return Name;
        }
    }

    public class MachineUser
    {

        public int Id { get; set; }
        public string Username { get; set; }
        public bool Active { get; set; }
        public string Email { get; set; }
        public string Agent_Version { get; set; }
        public int Group_Id { get; set; }
        public int Organization_id { get; set; }
        public string Domain { get; set; }
    }