class Student { String name; int age; List courses; final String? image; final String? id; Student(this.name, this.age, this.courses, {this.image, this.id}); static String getYearWord(int age) { if (age == -1) { return "Undefined"; } if (age % 10 == 1) { return age.toString() + " год"; } else if (age % 10 < 5 && age % 10 != 0) { return age.toString() + " года"; } else { return age.toString() + " лет"; } } void displayInfo() { print('Name: $name, Age: $age'); print('Courses: ${courses.join(", ")}'); } }