public bool EstimateStudent(ICourseForTeacher course, IStudent student, ITeacher teacher, double mark)
        {
            Course curCourse = course as Course;

            if (!curCourse.Equals(null))
            {
                if (curCourse.students.Contains(student))
                {
                    curCourse.markedStudents.Add(student, mark);
                }
            }
            return(false);
        }
        public bool FinishCourse(ICourseForTeacher course)
        {
            Course curCourse = course as Course;

            if (!curCourse.Equals(null))
            {
                if (currentCourses.Remove(curCourse))
                {
                    finishedCourses.Add(curCourse);
                    return(true);
                }
            }
            return(false);
        }
 public bool EstimateStudentByMark(ICourseForTeacher course, IStudent student, ITeacher teacher, double mark)
 {
     return(repository.EstimateStudent(course, student, teacher, mark));
 }
 public bool FinishCourse(ICourseForTeacher course)
 {
     return(repository.FinishCourse(course));
 }