public void T5_adding_teacher_to_student()
{
IStudent s = SchoolFactory.CreateStudent("Thibault Cam", 9, DateTime.Parse("21/02/1994"), "IL");
ITeacher t = SchoolFactory.CreateTeacher("Olivier Spineli", "C#", "IL", DateTime.Parse("21/02/1994"), true);
Action action = (() => s.AddTeacher(null));
action.Should().Throw <ArgumentNullException>();
s.AddTeacher(t);
s.MainTeacher.Should().NotBeNull();
s.MainTeacher.Should().BeEquivalentTo(t);
}