public bool IsOlderThan(Student studentToCompare)
        {
            if (studentToCompare.GetType() != typeof(Student))
            {
                throw new ArgumentException(String.Format(TYPE_ERROR_MSG, studentToCompare.GetType(), typeof(Student)));
            }

            DateTime ageOfCurrentStudent = GetBirth(this);
            DateTime ageOfOtherStudent = GetBirth(studentToCompare);
            bool isOlder = ageOfCurrentStudent > ageOfOtherStudent;

            return isOlder;
        }