A default constructor that initializes the Courses property to an instance of List<Course>

using System.Collections.Generic
namespace Treehouse.CodeChallenges
{
    public class Course
    {
        public int Id { get; set; }
        public int TeacherId { set; get;}
        public string Title { get; set; }
        public string Description { get; set; }
        public int Length { get; set; }
        public Teacher Teacher { set; get;}

        public ICollection<Courses> { get; set; }




    }
}

namespace Treehouse.CodeChallenges
{
    public class Teacher
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }
}