How to do Multiple ThenInclude navigation props after One Include

For a TestType I wanted to include both navigation props Schoolclass and Subject.

I could do a:

.Include(t => t.TestType)
 .ThenInclude(x => x.Subject)

but not a:

.Include(t => t.TestType)
.ThenInclude(x => x.Subject)
.ThenInclude(x => x.Schoolclass)

Thus I tried a little trick and that worked:

I included the TestType 2 times...

var test = await context.Tests.Where(t => t.SchoolyearId == schoolyearId)
                                          .Include(t => t.TestType)
                                          .ThenInclude(x => x.Subject)
                                           .Include(t => t.TestType)
                                          .ThenInclude(x => x.Schoolclass)
                                           .AsNoTracking()
                                          .ToListAsync();

Is that the official approach or is there a better one?

UPDATE

   public class TestType
    {
        public TestType()
        {
            Tests = new HashSet<Test>();
        }

        public int Id { get; set; }
        public string Name { get; set; }
        public int Weight { get; set; }
        public ISet<Test> Tests { get; set; }
        public Schoolyear Schoolyear { get; set; }  
        public Schoolclass Schoolclass { get; set; }   
        public Subject Subject { get; set; }
        public int SchoolyearId { get; set; }
    }