public void AddGrade(string subjectName, double value, DateTime date)
{
Grade grade = new Grade(subjectName, value, date);
_grades.Add(grade);
}
public void AddGrade(Grade grade)
{
AddGrade(grade.SubjectName, grade.Value, grade.Date);
}
public void DeleteGrade(Grade grade)
{
DeleteGrade(grade.SubjectName, grade.Value, grade.Date);
}