Day represents the school day (the row in the schedule table) that contains eight Lessons.

IncorrectDateError is returned when the date does not match the "dd.mm" format or does not exist.

IncorrectLinkError is returned when when the schedule on the link does not match the expected schedule.

IncorrectWeekNumberError is returned when the value of the school week number is out of the acceptable range.

Lesson represents the lesson (the cell in the schedule table) that can contain one or more SubLessons.

Schedule represents the full schedule that contains two school Weeks.easyjson:json.

StatusCodeError is returned when a http.Get returns a response with a status code other than 200.

SubLesson represents the nested lesson.

UnavailableScheduleError is returned when the week schedule is missing or not published.

Week represents the school week (one of two schedule tables) that contains seventh Days.

Duration represents the lesson's duration.

LessonType is the type of the lesson.

ScheduleType is the type of the schedule.