public void CheckUniqueNumber()
        {
            School  school  = new School();
            Course  course  = new Course();
            Student student = new Student();

            student.NameOfStudent   = "Roman";
            student.Age             = 29;
            student.NumberOfStudent = 22222;
            Student studentSecond = new Student();

            studentSecond.NameOfStudent   = "Ivan";
            studentSecond.Age             = 15;
            studentSecond.NumberOfStudent = 33333;
            school.AddObserver(student, course);
            var        listOfStudents   = school.GetListOfStudents();
            List <int> numbersOfStudent = new List <int>();

            foreach (var item in listOfStudents)
            {
                numbersOfStudent.Add(item.NumberOfStudent);
            }
            List <int> toCompare = numbersOfStudent.Distinct().ToList();

            foreach (var item in school.GetListOfStudents())
            {
                Assert.AreEqual(numbersOfStudent, toCompare);
            }
        }
        public void CheckName()
        {
            School  school  = new School();
            Course  course  = new Course();
            Student student = new Student();

            student.NameOfStudent   = "Roman";
            student.Age             = 29;
            student.NumberOfStudent = 22222;
            Student studentSecond = new Student();

            studentSecond.NameOfStudent   = "Ivan";
            studentSecond.Age             = 15;
            studentSecond.NumberOfStudent = 33333;
            school.AddObserver(student, course);
            foreach (var item in school.GetListOfStudents())
            {
                Assert.IsNotNull(item);
            }
        }